20 research outputs found
Synthesis, characterization, and photocatalytic efficiency of a new smart PdO oxide nanomaterials for using in the recycling and sustainable wastewater treatment
Nanostructured PdO materials with promising catalytic properties were successfully synthesized by the controlled thermal decomposition in air of three Pd(II) complexes containing Pd(II) ion, ofloxacin drug and amino acid. The Pd(II) complexes which were used as precursors were [Pd(OFL)(Gly)]Cl, [Pd(OFL)(Ala)]Cl, and [Pd(OFL)2]Cl2, where Gly is glycine amino acid, Ala is alanine amino acid, and OFL is ofloxacin. Structural and morphological properties of the synthesized PdO materials were obtained using FTIR, XRD, SEM, and EDX techniques. The XRD results confirm the tetragonal structure of PdO. The obtained PdO materials were tested as a catalyst for the heterogeneous degradation of H2O2 solution. The results revealed that PdO could effectively degrade H2O2.
KEY WORDS: PdO, Nanoparticles, Photocatalytic efficiency, Wastewater treatment
Bull. Chem. Soc. Ethiop. 2021, 35(1), 107-118.
DOI: https://dx.doi.org/10.4314/bcse.v35i1.
Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey
Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020
Carbon nanotubes-nanoporous anodic alumina composite membranes: influence of template on structural, chemical, and transport properties
This work presents the synthesis of carbon nanotubes−nanoporous anodic alumina composite membranes (CNTs−NAAMs) with controllable geometric features by a template-assisted catalyst-free chemical vapor deposition (CVD) approach using a mixture of toluene and ethanol as a carbon precursor. NAAMs templates were prepared by anodization of aluminum substrates in different electrolytes containing sulfuric, oxalic, and phosphoric acids with the aim of establishing the template effect on the CNTs growth. The deposition time during the CVD process was systematically modified to determine the formation mechanism of CNTs inside the pores of NAAMs without using metal catalysts. The structural features, chemical composition, and graphitic structures of the resulting CNTs−NAAMs composites were characterized by different techniques to provide a comprehensive understanding of the effect of the template on the formation of these carbon-based nanostructures. CNTs−NAAMs with inner pore diameters ranging from 15 to 180 nm were used. Our results reveal that the electrolyte type used to prepare NAAMs and the deposition time during the CVD process have a direct impact on the structural, chemical, and graphitic structural features of CNTs−NAAMs. The molecular transport properties of CNTs−NAAMs composite membranes featuring different geometries and chemical compositions were evaluated via the diffusion process of Rose Bengal, a dye model molecule. The obtained results show that the diffusional flux of the dye molecules can be controlled by tuning the inner pore diameter of CNTs deposited inside NAAMs, and the smaller the diameter of the nanotubes the faster the transport of dye molecules is. Our results provide novel insights into the fabrication of different CNTs composite membranes, establishing for the first time the influence of three common types of NAAMs templates on the properties of the resulting CNTs composite membranes. Our study enables the precise engineering of advanced CNTs composite membranes with controlled physical and chemical properties suitable for specific applications.Mohammed Alsawat, Tariq Altalhi, Abel Santos, and Dusan Losi
Facile and controllable route for nitrogen doping of carbon nanotubes composite membranes by catalyst-free chemical vapour deposition
Abstract not availableMohammed Alsawat, Tariq Altalhi, Abel Santos, Dusan Losi
Influence of surface chemistry on the ionic conductivity of vertically aligned carbon nanotube composite membranes
The nano-sized solid state pores and channels that mimic nature-based systems have attracted great interest due their potential applications for molecular separation, sensing, drug delivery, and energy conversion. In this study, in order to gain more knowledge on the ion and molecular transport inside nanopores, we examined how the surface conduction and electrochemical properties of carbon nanotubes (CNTs) composite membranes produced by a template-assisted catalyst-free chemical vapour deposition (CVD) process using nanoporous anodic alumina membranes (NAAMs) as a template can be tuned readily by chemical modification of their inner surface for various applications. The inner graphitic surface of the resulting CNTs was modified chemically through wet oxidation process using hydrogen peroxide (H₂O₂) as the oxidant agent to introduce oxygen-containing groups, mainly carboxyl groups. Electrochemical impedance spectroscopy (EIS) revealed significant changes in surface conduction measured by impedance and conductance of CNTs as a result of the selective chemical modification of their inner wall surfaces. These results show that this approach makes it possible to tune the surface conductivity and interfacial properties of vertically aligned arrays of CNTs with precision, using a simple oxidation process. Therefore, this method can be used to produce CNTs composite membranes with precisely controlled electrochemical properties and conductivity related to potential applications of advanced electrically driven and bioinspired separation devices for water desalination and separation of biological molecules.Mohammed Alsawat, Krishna Kant, Tariq Altalhi, Abel Santos and Dusan Losi
Modulating molecular transport across peptide-modified nanoporous alumina membranes with light
Abstract not availableTushar Kumeria, Jingxian Yu, Mohammed Alsawat, Mahaveer D. Kurkuri, Abel Santos, Andrew D. Abell, Dusan Losi
Utilizing of (Zinc Oxide Nano-Spray) for Disinfection against “SARS-CoV-2” and Testing Its Biological Effectiveness on Some Biochemical Parameters during (COVID-19 Pandemic)—”ZnO Nanoparticles Have Antiviral Activity against (SARS-CoV-2)”
A newly synthesized zinc (II) oxide nanoparticle (ZnO-NPs) has been used as a disinfectant Nano-spray for the emerging corona virus (SARS-CoV-2). The synthesized obtained nanomaterial of (ZnO) was fully chemically characterized by using different spectroscopic analysis (FT-IR, UV and XRD) and surface analysis techniques. ZnO-Nps surface morphology and chemical purity has been investigated by transmission electron microscope (TEM), high resolution transmission electron microscope (HR-TEM), scanning electron microscopy (SEM) as well as energy dispersive X-ray analysis (EDX), Additionally Zeta potential and Zeta size distribution were measured and evaluated to confirm its nano-range scale. The synthesized Zno-NPs have been tested using 10% DMSO and ddH2O for estimation of antiviral activity against (SARS-CoV-2) by using cytotoxicity assay (CC50) and inhibitory concentration (IC50). The results revealed that (Zno-NPs) has high anti-SARS-CoV-2 activity at cytotoxic concentrations in vitro with non-significant selectivity index (CC50/IC50 ≤ 1). The current study results demonstrated the (ZnO-NPs) has potent antiviral activity at low concentration (IC50 = 526 ng/mL) but with some cytotoxic effect to the cell host by (CC50 = 292.2 ng/mL). We recommend using of (ZnO-NPs) as potent disinfectant against (SARS-Cov-2), but there are slight side effects on the cellular host, so we recommend more prospective studies on complexation of other compounds with (ZnO-NPs) in different concentrations to reduce its cellular toxicity and elevate its antiviral activity against SARS-CoV-2 activities
Photoswitchable membranes based on peptide-modified nanoporous anodic alumina: toward smart membranes for on-demand molecular transport
Abstract not availableTushar Kumeria, Jingxian Yu, Mohammed Alsawat, Mahaveer D. Kurkuri, Abel Santos, Andrew D. Abell, and Dusan Losi
Boost the Crystal Installation and Magnetic Features of Cobalt Ferrite/M-Type Strontium Ferrite Nanocomposites Double Substituted by La3+ and Sm3+ Ions (2CoFe2O4/SrFe12−2xSmxLaxO19)
Spinel cobalt ferrite/hexagonal strontium hexaferrite (2CoFe2O4/SrFe12−2xSmxLaxO19; x = 0.2, 0.5, 1.0, 1.5) nanocomposites were fabricated using the tartaric acid precursor pathway, and the effects of La3+–Sm3+ double substitution on the formation, structure, and magnetic properties of CoFe2O4/SrFe12−2xSmxLaxO19 nanocomposite at different annealing temperatures were assayed through X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. A pure 2CoFe2O4/SrFe12O19 nanocomposite was obtained from the tartrate precursor complex annealed at 1100 °C for 2 h. The substitution of Fe3+ ion by Sm3–+La3+ions promoted the formation of pure 2CoFe2O4/SrFe12O19 nanocomposite at 1100 °C. The positions and intensities of the strongest peaks of hexagonal ferrite changed after Sm3+–La3+ substitution at ≤1100 °C. In addition, samples with an Sm3+–La3+ ratio of ≥1.0 annealed at 1200 °C for 2 h showed diffraction peaks for lanthanum cobalt oxide (La3Co3O8; dominant phase) and samarium ferrite (SmFeO3). The crystallite size range at all constituent phases was in the nanocrystalline range, from 39.4 nm to 122.4 nm. The average crystallite size of SrFe12O19 phase increased with the number of Sm3+–La3+ substitutions, whereas that of CoFe2O4 phase decreased with an x of up to 0.5. La–Sm co-doped ion substitution increased the saturation magnetization (Ms) value and the subrogated ratio to 0.2, and the Ms value decreased with the increasing number of double substitutions. A high saturation magnetization value (Ms = 69.6 emu/g) was obtained using a La3+–Sm3+ co-doped ratio of 0.2 at 1200 for 2 h, and a high coercive force value (Hc = 1192.0 Oe) was acquired using the same ratio at 1000 °C
Shared Situational Awareness within the Hospital Emergency Context: A Scoping Review
Background. Shared Situation Awareness (SSA) has been applied in many fields such as sport, the military and aviation with promising outcomes on team performance. The application of SSA within the hospital emergency healthcare context has not been explored yet. The aim of this scoping review is to explore and map literature related to shared situational awareness within the hospital emergency healthcare context. Methods. The Arksey and O’Malley (2005) framework was used in which three electronic databases were searched for evidence investigating SSA within a hospital emergency healthcare context. Results. A review of the literature showed a clear lack of evidence that directly investigates SSA within the context of hospital emergency care. In the emergency medical field, the term SSA is seldom used and ‘team situation awareness’ is the most frequently used term. The most common framework was the three-level framework. Two techniques were reported in the selected studies to investigate SSA (1) freeze probe technique and (2) observer-based rating technique. The freeze probe technique mandates a simulation or artificial environment, while the observer-based rating technique could be applied in an ecological as well as an artificial environment. There is no standardized technique to calculate the score of the SSA. Finally, there was a significant impact of SSA on clinical team performance as well as some related skills such as leadership, task management, mindfulness and task prioritization. Conclusions. Reviewing the literature revealed a lack of studies investigating the use of SSA within the context of hospital emergency care. There is also a lack of agreement on how a SSA score should be calculated. Further studies are required to overcome these issues