Influence of Precursor Compounds on the Structural and Catalytic Properties of Cobalt-Based Catalysts

The effects of different cobalt precursor compounds on the structural and catalytic properties of cobalt metal and Co 3 O 4 catalysts have been investigated. The techniques employed for characterizing the different solids were XRD, ESR and TEM methods, together with their effectiveness as catalysts in the decomposition of H 2 O 2 at 30–50 °C. The results obtained indicate that the investigated catalysts contained clusters or very small particles of cobalt metal or Co 3 O 4 phases. Cobalt metal and Co 3 O 4 catalysts based on cobalt chloride exhibited higher catalytic activities than other catalysts derived from cobalt nitrate and sulphate salts, respectively, due to their decreased particle sizes. The activation energies of the catalytic reaction over the as-prepared catalysts revealed that the different precursor compounds did not modify the energetic nature of the active sites involved in the catalyzed reaction but changed their concentrations

Novel cationic surfactants from fatty acids and their corrosion inhibition efficiency for carbon steel pipelines in 1 M HCl

Four fatty acids were used as a source of alkyl halides. Untraditionally tertiary amines were prepared by ethoxylation of aromatic and aliphatic fatty amines. These alkyl halide and tertiary amines were used to prepare 20 cationic quaternary ammonium surfactants (QASS). Their chemical structures were characterized and they tested as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency was measured using, weight loss and potentiodynamic polarization methods. The inhibition efficiencies obtained from the two employed methods are nearly closed. From the obtained data it was found that, the inhibition efficiency increases with increasing the inhibitor concentration until the optimum one. Also, it was found that the inhibition efficiency of QASs which based on ethoxylated aromatic tertiary amine is greater than the obtained efficiencies by the QASs which based on ethoxylated aliphatic tertiary amines. The QASs based on alkyl halide C16 exhibited the maximum inhibition efficiency 98.8%. Adsorption of the inhibitors on the carbon steel surface was found to obey Langmuir’s adsorption isotherm. The quantum chemical calculations were done for some selected quaternary ammonium compounds based on their chemical structures QL1,4,5–QP3,4,5. The following quantum chemical indices such as the bond length, bond angle, charge density distribution, highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap ΔE = HOMO − LUMO, and dipole moment (u) were considered. The relation between these parameters and the inhibition efficiencies was explained on the light of the chemical structure of the used inhibitors

Needle‐Free Jet Injectors for Dermal and Transdermal Delivery of Actives

Needle‐free jet injectors are medical devices used for the delivery of liquid medications across the skin as a high‐speed stream of fluid, without the use of a needle. The absence of a needle abolishes the risk of needle‐stick injuries, frequent among healthcare providers, and increases the compliance to injections in needle‐phobic patients. Through the modulation of several parameters of the jet injectors, the liquid medication can be delivered to different sites within or below the skin, thus allowing the use of such devices for both local and systemic therapies in a multitude of disorders. In the present chapter, after a brief historical overview, the functioning principles and the rationale behind the use of needle‐free jet injectors are presented. Moreover, preclinical and clinical studies where jet injectors have been employed for the systemic or local delivery of therapeutics are reviewed. Finally, in the last section, the potential of such devices for the administration of nano‐ and micro‐particulate drug delivery systems is discussed

Contribution of Biologic Response Modifiers to the Risk of Coccidioidomycosis Severity

Background: The risk of coccidioidomycosis (CM) as a life-Threatening respiratory illness or disseminated CM (DCM) increases as much as 150-fold in immunosuppressed patients. The safety of biologic response modifiers (BRMs) as treatment for patients with autoimmune disease (AI) in CM-endemic regions is not well defined. We sought to determine that risk in the Tucson and Phoenix areas. Methods: We conducted a retrospective study reviewing demographics, Arizona residency length, clinical presentations, specific AI diagnoses, CM test results, and BRM treatments in electronic medical records of patients ≥18 years old with International Classification of Diseases (ICD-10) codes for CM and AI from 1 October 2017 to 31 December 2019. Results: We reviewed 944 charts with overlapping ICD-10 codes for CM and AI, of which 138 were confirmed to have both diagnoses. Male sex was associated with more CM (P =. 003), and patients with African ancestry were 3 times more likely than those with European ancestry to develop DCM (P <. 001). Comparing CM+/AI+ (n = 138) with CM+/AI- (n = 449) patients, there were no significant differences in CM clinical presentations. Patients receiving BRMs had 2.4 times more DCM compared to pulmonary CM (PCM). Conclusions: AI does not increase the risk of any specific CM clinical presentation, and BRM treatment of most AI patients does not lead to severe CM. However, BRMs significantly increase the risk of DCM, and prospective studies are needed to identify the immunogenetic subset that permits BRM-Associated DCM. © Published by Oxford University Press on behalf of Infectious Diseases Society of America 2022.Public domain articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]