Multi-pollutant biosorption of organic and inorganic pollutants by brown algae waste from alginate production: batch and fixed-bed investigation

The reuse of biomass waste has been gaining attention in adsorption processes to remove pollutants of emerging concern from water and wastewater. In this work, the potential of alginate-extracted macro-algae waste to uptake synthetic dyes and metal cations was evaluated in comparison with raw algae. In affinity assays, both materials were able to remove metal cations and cationic dyes up to maximum rates, and no significant removal was observed for an anionic dye in an acidic medium. Competition was observed in multi-component systems of metal cations and dyes. For binary samples containing organic and inorganic contaminants, kinetic modeling evidenced the distinct nature of both types of adsorbates. Pb(II) biosorption was best described as a first-order process, while second-order and Elovich models better fitted methyl blue (MB) uptake data. For equimolar binary samples, the Sips isothermal model fitted the experimental data more satisfactorily at room temperature. Isotherms for 20, 30, 40, and 60 °C exhibited favorable adsorption profiles with spontaneous ΔG values for both raw macro-algae and waste from alginate extraction. Maximum adsorption capacities were competitive with previous reports in the literature for a wide range of biomaterials, pointing to the slightly higher efficiency with algae waste in batch experiments. In elution tests, HNO3 (0.5 M) showed the best recovery rates of metal cations. Continuous biosorption operation revealed the performance of the brown algae waste was considerably more efficient than raw algae with breakthrough biosorption capacities up to 3.96 and 0.97 mmol.g-1 for the removal of Pb(II) and MB, respectively. A total of 3.0 g of algae and algae waste were able to deliver 1.20 and 1.62 L of contaminant-free water, respectively. XPS analyses corroborate previous assays that pointed to the prevalence of physisorption with evidence of complexation, ionic exchange, and hydrogen displacement mechanisms.

Unravelling the surface structure of β-Ga2O3 (100)

The present work is on a comprehensive surface atomic structure investigation of β-Ga2O3 (100). The β-Ga2O3 single crystal was studied by a structural model system in the simulations and in situ characterization via X-ray photoelectron spectroscopy (XPS), low-energy electron diffraction (LEED) and X-ray photoelectron diffraction (XPD) allowed for probing the outermost layers' properties. In situ XPD characterization allows for the collection of valuable element-specific short-range information from the β-Ga2O3 surface, and the results were compared to a systematic and precise multiple scattering simulation approach. The experiments, characterizations, and simulations indicated strong evidence of considerable structural variations in the interatomic layer's distances. Such atomic displacement could clarify the electronic phenomena observed in theoretical studies. The comparison between experimental and theoretical XPD results involving multiple scattering calculations indicated that the β-Ga2O3 surface has two possible terminations. The best fits to the photoelectron diffraction curves are used to calculate the interplanar relaxation in the first five atomic layers. The results show good agreement with previous density functional theory calculations, establishing XPD as a useful tool for probing the atomic structure of oxide surfaces.

7 LEARNING FROM THE FALLS ANALYSIS OF OLDER PEOPLE ADMITTED TO AN IRISH POST-ACUTE REHABILITATION SERVICE

Background

Thirty percent of community-dwelling older adults fall each year with 10% suffering a severe injury often resulting in hospital admission. To deliver effective falls prevention a thorough falls history is required. The objective of this study was to complete a SPLATT (symptoms before fall, previous falls, location of fall, activity at time of fall, time of day and trauma sustained) analysis of falls that resulted in an acute hospital admission reported by older people on admission to the post-acute rehabilitation unit.

Methods

Older people admitted to rehabilitation post fall that resulted in acute admission were included in this study. The SPLATT analysis was completed on OT initial assessment. Data was anonymized and recorded using Microsoft excel.

Results

A total of 61 falls were included in the analysis. Participants were all older people admitted to post-acute rehabilitation (female= 48, male= 13). 93% reported no symptoms before their fall. Almost half (43%) had experienced previous falls. Most falls (51%) happened at home with most of these (29%) occurring in the bedroom. A significant proportion (30%) happened in the community. The most common cause of fall was a loss of balance (32%) while completing a reaching or functional task. Most falls (87%) happened during the day but of those who fell at night, 62.5% occurred while trying to use the toilet. The majority (82%) of the falls lead to a significant trauma – hip fracture.

Conclusion

The results of this study supports that falls prevention interventions for rehabilitation service users should incorporate functional training both at home and in the community. The individual SPLATT analysis could support the design of a falls prevention intervention tailored to the person’s needs and history.

Case Report: Thrombotic-Thrombocytopenic Purpura Following Ipilimumab and Nivolumab Combination Immunotherapy for Metastatic Melanoma

A man in his early 50s presented with small bowel obstruction, requiring emergency laparoscopic small bowel resection for the metastatic melanoma of the jejunum with no identifiable primary lesion. One week after his first treatment with ipilimumab and nivolumab, he presented with diffuse abdominal pain, constipation, and fatigue. A computerized tomography scan did not identify a cause for his symptoms. This was rapidly followed by thrombocytopenia on day 11 and then anemia. He commenced intravenous corticosteroids for a suspected diagnosis of immune-related thrombocytopenia. On day 15, a generalized onset motor seizure occurred, and despite plasmapheresis later that day, the patient died from fatal immune-related thrombotic thrombocytopenic purpura (TTP). This was confirmed with suppressed ADAMTS13 (<5%) testing on day 14. Immune-related TTP is a rare and, in this case, fatal immune- related adverse event. Further studies are required to identify additional immunosuppressive management for immune-related TTP.

Evidencing the formation of Pt nano-islands on Cr2O3/Ag(111)

The present work reports on a comprehensive surface atomic structure investigation on the Pt/Cr2O3/Ag(111) model catalyst. Molecular beam epitaxy (MBE) was applied to achieve the Pt/Cr2O3 model system and in...

Synthesis, characterization and in vitro cytotoxicity study of Co and Ni ferrite nanoparticles prepared by sol-gel method

In this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.

Selecting 'convenient observers' to probe the atomic structure of CVD graphene on Ir(111) via photoelectron diffraction

CVD graphene grown on metallic substrates presents, in several cases, a long-range periodic structure due to a lattice mismatch between the graphene and the substrate. For instance, graphene grown on Ir(111), displays a corrugated supercell with distinct adsorption sites due to a variation of its local electronic structure. This type of surface reconstruction represents a challenging problem for a detailed atomic surface structure determination for experimental and theoretical techniques. In this work, we revisited the surface structure determination of graphene on Ir(111) by using the unique advantage of surface and chemical selectivity of synchrotron-based photoelectron diffraction. We take advantage of the Ir 4f photoemission surface state and use its diffraction signal as a probe to investigate the atomic arrangement of the graphene topping layer. We determine the average height and the overall corrugation of the graphene layer, which are respectively equal to 3.40 ± 0.11 Å and 0.45 ± 0.03 Å. Furthermore, we explore the graphene topography in the vicinity of its high-symmetry adsorption sites and show that the experimental data can be described by three reduced systems simplifying the moiré supercell multiple scattering analysis.

Outlining cell interaction and inflammatory cytokines on UV-photofunctionalized mixed-phase TiO2 thin film

Photofunctionalization mediated by ultraviolet (UV) light seems to be a promising approach to improve the physico-chemical characteristics and the biological response of titanium (Ti) dental implants. Seeing that photofunctionalization is able to remove carbon from the surface, besides to promote reactions on the titanium dioxide (TiO₂) layer, coating the Ti with a stable TiO₂ film could potentialize the UV effect. Thus, here we determined the impact of UV-photofunctionalized mixed-phase (anatase and rutile) TiO₂ films on the physico-chemical properties of Ti substrate and cell biology. Mixed-phase TiO₂ films were grown by radiofrequency magnetron sputtering on commercially pure titanium (cpTi) discs, and samples were divided as follow: cpTi (negative control), TiO₂ (positive control), cpTi UV, TiO₂ UV (experimental). Photofunctionalization was performed using UVA (360 nm - 40 W) and UVC (250 nm - 40 W) lamps for 48 h. Surfaces were analyzed in terms of morphology, topography, chemical composition, crystalline phase, wettability and surface free energy. Pre-osteoblastic cells (MC3T3E1) were used to assess cell morphology and adhesion, metabolism, mineralization potential and cytokine secretion (IFN-γ, TNF-α, IL-4, IL-6 and IL-17). TiO₂-coated surfaces exhibited granular surface morphology and greater roughness. Photofunctionalization increased wettability (p < 0.05) and surface free energy (p < 0.001) on both surface conditions. TiO₂-treated groups featured normal cell morphology and spreading, and greater cellular metabolic activity at 2 and 4 days (p < 0.05), whereas UV-photofunctionalized surfaces enhanced cell metabolism, cell adhered area, and calcium deposition (day 14) (p < 0.05). In general, assessed proteins were found slightly affected by either UV or TiO₂ treatments. Altogether, our findings suggest that UV-photofunctionalized TiO₂ surface has the potential to improve pre-osteoblastic cell differentiation and the ability of cells to form mineral nodules by modifying Ti physico-chemical properties towards a more stable context. UV-modified surfaces modulate the secretion of key inflammatory markers.

Physicochemical Studies on the Surface of Polyamide 6.6 Fabrics Functionalized by DBD Plasmas Operated at Atmospheric and Sub-Atmospheric Pressures

This work proposes the use of a dielectric barrier discharge (DBD) reactor operating at atmospheric pressure (AP) using air and sub-atmospheric pressure (SAP) using air or argon to treat polyamide 6.6 (PA6.6) fabrics. Here, plasma dosages corresponding to 37.5 kW·min·m-2 for AP and 7.5 kW·min·m-2 for SAP in air or argon were used. The hydrophilicity aging effect property of untreated and DBD-treated PA6.6 samples was evaluated from the apparent contact angle. The surface changes in physical microstructure were studied by field emission scanning electron microscopy (FE-SEM). To prove the changes in chemical functional groups in the fibers, Fourier transform infrared spectroscopy (FTIR) was used, and the change in surface bonds was evaluated by energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). In addition, the whiteness effect was investigated by the color spectrophotometry (Datacolor) technique. The results showed that the increase in surface roughness by the SAP DBD treatment contributed to a decrease in and maintenance of the hydrophilicity of PA6.6 fabrics for longer. The SAP DBD in air treatment promoted an enhancement of the aging effect with a low plasma dosage (5-fold reduction compared with AP DBD treatment). Finally, the SAP DBD treatment using argon functionalizes the fabric surface more efficiently than DBD treatments in air.

Treatment of aqueous solutions of 1,4-dioxane by ozonation and catalytic ozonation with copper oxide (CuO)

In this study, treatment for the removal of 1,4-dioxane by ozone and by catalytic ozonation using CuO as the catalyst was investigated. While the removal of 1,4-dioxane was small (20%) and mineralization negligible after 6 h of ozonation treatment, the removals of 1,4-dioxane and total organic carbon increased by factors of 10.35 and 81.25, respectively, after catalytic ozonation in the presence of CuO. The mineralization during catalytic ozonation was favoured at pH 10 (94.91 min^-1), although it proceeded even at pH 3 (54.41 min^-1). The CuO catalyst decreased the equilibrium concentration of soluble ozone and favoured its decomposition to reactive oxidative species. Radical scavenging experiments demonstrated that superoxide radicals were the main species responsible for the degradation of 1,4-dioxane. Further scavenging experiments with phosphate confirmed the presence of Lewis active sites on the surface of CuO, which were responsible for the adsorption and decomposition of ozone. The reaction mechanism proceeded through the formation of ethylene glycol diformate, which quickly hydrolyzed to ethylene glycol and formic acid as intermediate products. The stability of CuO indicated weak copper leaching and high catalytic activity for five recycling cycles. The toxicity of the water, assessed by Vibrio fischeri bioluminescence assays, remained the same (low toxicity) after catalytic ozonation while it increased after treatment with ozonation alone.

Metallic copper removal optimization from real wastewater using pulsed electrodeposition

The recovery of metals from wastewater is a recurrent problem due to numerous productive activities that produce wastewaters rich in toxic metals. Within this context, this research presents the study and optimization of copper recovery of real wastewater using pulsed electrodeposition. The studied parameters - method, current, temperature, and rotation- influence both the removal of Cu and the composition of the formed deposit, noting that the variation of these parameters enables the removal of copper with formation from crystalline oxides to crystalline copper in its metallic form. The process was optimized, and a 33.59% copper removal from a real wastewater with a deposition efficiency of 84.36% in 30 min was deemed optimal, using fast galvanic pulse, t_on = 1 ms, 190 mA, 70 rpm, and 37 °C. For coating in the optimum point, a metallic and crystalline copper with 100% purity was obtained.

Equilibrium study of binary mixture biosorption of Cr(III) and Zn(II) by dealginated seaweed waste: investigation of adsorption mechanisms using X-ray photoelectron spectroscopy analysis

The alginate extraction residue (RES) from the Brazilian Sargassum filipendula was successfully employed as biosorbent in this binary equilibrium study, revealing a greater affinity and selectivity for Cr(III) than for Zn(II). Experimental results also revealed that the process is of endothermic nature and well adjusted by Langmuir-Freundlich binary model. The X-ray photoelectron spectroscopy (XPS) analysis revealed that coordination with hydroxyl groups of RES prevailed in Cr removal, followed by carboxyl-metal complexation. As far as Zn(II) is concerned, ion exchange with carboxylate groups of RES was the largest contributor. Nevertheless, scanning electron microscopy coupled with Fourier transform infrared spectroscopy indicated the participation of sulfate functions in a minor degree.

3D Printed Graphene Electrodes Modified with Prussian Blue: Emerging Electrochemical Sensing Platform for Peroxide Detection

3D printing technologies have been considered an important technology due to the ease manufacturing of objects, freedom of design, waste minimization, and fast prototyping. In chemistry, this technology potentializes the fabrication of conductive electrodes in large scale for sensing applications. Herein, we reported the modification of a 3D printed graphene electrode with Prussian blue. The modified electrode (3DGrE/PB) was characterized by microscopy (SEM and AFM) and spectroscopic techniques, and its electrochemical properties were compared to the traditional electrodes: glassy carbon, gold, and platinum. The 3DGrE/PB was used in the sensing of hydrogen peroxide in real-world samples of milk and mouthwash, and the results obtained according to the technique of batch-injection analysis were satisfactory for the concentration range typically found in such samples. Thus, 3DGrE/PB can be used as a new platform for sensing of molecular targets.

Catalytic oxidation at pilot-scale: Efficient degradation of volatile organic compounds in gas phase

Volatile organic compounds (VOCs) are responsible for environmental problems and may affect human health. Several treatment technologies minimize VOCs emissions; among those, catalytic oxidation appears as a promising alternative. In this study, a pilot-scale catalytic reactor was developed and the influence of process parameters on toluene degradation were investigated. Inlet gases were heated by electrical resistances and the catalyst employed was a honeycomb shape commercial automotive catalyst (Umicore, model AFT). Toluene degradation higher than 99% was achieved for several conditions and temperature showed to be the most important process variable for it. For all concentrations, it was observed that when increasing temperature led to a decrease on the space time. At 800 ppmv, varying from 543 K to 633 K, the space time decreased from 0.121 s to 0.08 s, respectively. At 1600 ppmv for the same temperature range, space time was reduced from 0.098 s to 0.040 s, respectively. At 2400 ppmv, varying from 543 K to 633 K, space time decreased from 0.081 s to 0.048 s. The catalytic reactor developed proved to be efficient for VOCs treatment, showing a high potential of application at industrial emission sources.

Electrochemical water oxidation by cobalt-Prussian blue coordination polymer and theoretical studies of the electronic structure of the active species

The search for earth-abundant metal-based catalysts for the oxygen evolution reaction (OER) that operates in neutral conditions is a challenge in the field of sustainable energy.

Análise Físico-Química e Resistência ao Cisalhamento de Zircônia em Cimentos Resinosos Após Tratamento com Plasma Não-Térmico e/ou Primer

O objetivo deste estudo foi caracterizar a superfície de Y-TZP tratadas com NTP, primer para ligas metálicas ou a associação entre esses dois métodos, e avaliar o efeito desses tratamentos na resistência de união entre Y-TZP e dois cimentos resinosos. Discos de Y-TZP foram distribuídos em cinco grupos: Co (sem tratamento), Pr (primer), NTP (plasma de metano), Pr + NTP e NTP + Pr. Os discos foram cimentados em substratos de resina composta utilizando Panavia F2.0 ou RelyX U200. As análises de resistência ao cisalhamento (n 10) foram realizadas antes e após termociclagem. Os dados foram submetidos à ANOVA um e três fatores e teste de Bonferroni (a0,05). NTP reduziu a energia de superfície e a rugosidade dos discos de Y-TZP. As análises de morfologia e químicas mostraram a presença da película fina orgânica, o que melhorou significativamente os resultados de resistência de ligação quando foi utilizado Rely X U200, enquanto que o tratamento com primer foi mais eficaz com Panavia F2.0. A termociclagem reduziu significativamente os resultados de resistência de união dos grupos NTP e Pr + NTP cimentados com Rely X U200 e os grupos Pr e NTP + Pr cimentados com Panavia F2.0. O plasma não térmico melhorou a união entre Rely X U200 e Y-TZP e também parece ser resistente à degradação hidrolítrica, enquanto que o Panavia F2.0 apresentou os maiores valores de união quando associado ao primer.Palavras-chave: Resistência ao Cisalhamento. Cimentos Resinosos. Plasma de Pressão Atmosférica Não-Térmica.

Employing Calcination as a Facile Strategy to Reduce the Cytotoxicity in CoFe2O4 and NiFe2O4 Nanoparticles

CoFe₂O₄ and NiFe₂O₄ nanoparticles (NPs) represent promising candidates for biomedical applications. However, in these systems, the knowledge over how various physical and chemical parameters influence their cytotoxicity remains limited. In this article, we investigated the effect of different calcination temperatures over cytotoxicity of CoFe₂O₄ and NiFe₂O₄ NPs, which were synthesized by a sol-gel proteic approach, toward L929 mouse fibroblastic cells. More specifically, we evaluated and compared CoFe₂O₄ and NiFe₂O₄ NPs presenting low crystallinity (that were calcined at 400 and 250 °C, respectively) with their highly crystalline counterparts (that were calcined at 800 °C). We found that the increase in the calcination temperature led to the reduction in the concentration of surface defect sites and/or more Co or Ni atoms located at preferential crystalline sites in both cases. A reduction in the cytotoxicity toward mouse fibroblast L929 cells was observed after calcination at 800 °C. Combining with inductively coupled plasma mass spectrometry data, our results indicate that the calcination temperature can be employed as a facile strategy to reduce the cytotoxicity of CoFe₂O₄ and NiFe₂O₄, in which higher temperatures contributed to the decrease in the dissolution of Co²⁺ or Ni²⁺ from the NPs. We believe these results may shed new insights into the various parameters that influence cytotoxicity in ferrite NPs, which may pave the way for their widespread applications in biomedicine.

Separation technology meets green chemistry: development of magnetically recoverable catalyst supports containing silica, ceria, and titania

Magnetic separation can be considered a green technology because it is fast, efficient, consumes low energy, and minimizes the use of solvents and the generation of waste. It has been successfully used in laboratory scale to facilitate supported catalysts’ handling, separation, recovery, and recycling. Only few materials are intrisically magnetic, hence the application of magnetic materials as catalyst supports has broaden the use of magnetic separation. Iron oxides, silica-coated iron oxides, and carbon-coated-cobalt are among the most studied catalyst supports; however, other metal oxide coatings, such as ceria and titania, are also very interesting for application in catalysis. Here we report the preparation of magnetically recoverable magnetic supports containing silica, ceria, and titania. We found that the silica shell protects the iron oxide core and allows the crystalization of ceria and titania at high temperature without compromising the magnetic properties of the catalyst supports.

Development of binary and ternary titanium alloys for dental implants

OBJECTIVE

The aim of this study was to develop binary and ternary titanium (Ti) alloys containing zirconium (Zr) and niobium (Nb) and to characterize them in terms of microstructural, mechanical, chemical, electrochemical, and biological properties.

METHODS

The experimental alloys - (in wt%) Ti-5Zr, Ti-10Zr, Ti-35Nb-5Zr, and Ti-35Nb-10Zr - were fabricated from pure metals. Commercially pure titanium (cpTi) and Ti-6Al-4V were used as controls. Microstructural analysis was performed by means of X-ray diffraction and scanning electron microscopy. Vickers microhardness, elastic modulus, dispersive energy spectroscopy, X-ray excited photoelectron spectroscopy, atomic force microscopy, surface roughness, and surface free energy were evaluated. The electrochemical behavior analysis was conducted in a body fluid solution (pH 7.4). The albumin adsorption was measured by the bicinchoninic acid method. Data were evaluated through one-way ANOVA and the Tukey test (α=0.05).

RESULTS

The alloying elements proved to modify the alloy microstructure and to enhance the mechanical properties, improving the hardness and decreasing the elastic modulus of the binary and ternary alloys, respectively. Ti-Zr alloys displayed greater electrochemical stability relative to that of controls, presenting higher polarization resistance and lower capacitance. The experimental alloys were not detrimental to albumin adsorption.

SIGNIFICANCE

The experimental alloys are suitable options for dental implant manufacturing, particularly the binary system, which showed a better combination of mechanical and electrochemical properties without the presence of toxic elements.

Amphiphilic Nucleating Agents to Enhance Calcium Phosphate Growth on Polymeric Surfaces

Poly(ε-caprolactone) (PCL) is an aliphatic polyester widely explored in the preparation of guided bone regeneration (GBR) membranes because of its interesting mechanical properties and biodegradability. However, PCL high hydrophobicity often impairs cell adhesion and proliferation as well as calcium phosphate growth, all of which are crucial to achieving suitable bone-tissue integration. In this work, aimed at achieving less-hydrophobic surfaces, amphiphilic molecules were added at low concentrations to the polymeric dope solutions that generated the GBR membranes. During membrane formation, these molecules migrate to the solution/air interface in such a way that, upon liquid-solid phase transition, the negatively charged heads are exposed while the apolar tails are anchored to the polymer bulk. As a consequence, these molecules became nucleating agents for subsequent calcium phosphate growth using an alternating soaking process. Herein, PCL porous membranes containing different amphiphilic molecules, such as stearic acid and bis(2-ethylhexyl) phosphate, were investigated. This new, simple, and atoxic method to superficially treat polymeric membranes could be extended to a wide range of polymers and applications.

Photocatalytic oxidation of selected gas-phase VOCs using UV light, TiO2, and TiO2/Pd

Heterogeneous photocatalytic oxidation systems using titanium dioxide (TiO₂) have been extensively studied for the removal of several volatile organic compounds (VOCs). The addition of noble metals such as palladium on TiO₂ may improve photocatalytic activity by increasing charge separation efficiency. In this work, palladium was impregnated on TiO₂ and the efficiency of the new catalyst was tested and compared with that of pure TiO₂. Pd was impregnated on TiO₂ by the reduction method, using NaBH₄, and was characterized by XRD, XPS, UV-Vis, and H₂ chemisorption. The photocatalytic tests were performed in an annular coated-wall reactor using octane, isooctane, n-hexane, and cyclohexane at inlet concentrations varying from 100 to 120 ppmv. Compared with pure TiO₂ film, the photocatalytic activity of TiO₂ impregnated with 1 wt% of palladium was improved. All the aforementioned analytical techniques confirmed the presence of Pd incorporated into the structure of TiO_2, and the conversion rates were studied in a broad range of residence times, yielding up to 90 % or higher rates in 40 s of residence time, thus underscoring the relevant contribution of the technology.

University Hospital Waterford: 5-year experience of cutaneous melanoma

INTRODUCTION

The incidence of cutaneous melanoma (CM) continues to rise in Ireland. Despite significant advances in melanoma molecular therapy, surgery remains the mainstay of treatment for CM. The University Hospital Waterford (UHW) prospectively maintained CM registry was established in 2010.

AIM

To summarize 5-year experience (2010-2015) of primary CM presenting to UHW.

METHODS

Data were retrospectively obtained from a central electronic pathology and radiology repository augmented by HIPE data and theatre logs. Data collected included patient demographics and clinico-pathological characteristics, specimen number, size, anatomical location, melanoma subtype, Breslow thickness, Clark's level, ulceration, and mitosis.

RESULTS

592 CMs were managed in UHW during the study period. Overall, females comprised the majority of cases with mean age at presentation 60.78 ± 18.29 years. The most commonly affected anatomical location was the lower limb (26.7%) followed by the back (15.1%), upper limb (15.07%), and face (14.40%). Superficial spreading and lentigo maligna were the most common histological subtype accounting for 19.8 and 20%, respectively. Overall, the mean Breslow depth was 2.4 ± 3.7 mm with corresponding Clark's Level III. Sentinel lymph node positivity was 39/103 (37.89%) most commonly located in the axilla (53.8%) and groin (30.7%).

CONCLUSION

There has been a steady increase in the number of cutaneous melanoma presentations over the past 5-years to the South East Cancer Centre. Patients are managed best by prompt surgical excision and multidisciplinary management. Our results are in keeping with international standards and work continues in determining overall 5-year survival and recurrence rates.

Multitask Imidazolium Salt Additives for Innovative Poly(l-lactide) Biomaterials: Morphology Control, Candida spp. Biofilm Inhibition, Human Mesenchymal Stem Cell Biocompatibility, and Skin Tolerance

Candida species have great ability to colonize and form biofilms on medical devices, causing infections in human hosts. In this study, poly(l-lactide) films with different imidazolium salt (1-n-hexadecyl-3-methylimidazolium chloride (C16MImCl) and 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C16MImMeS)) contents were prepared, using the solvent casting process. Poly(l-lactide)-imidazolium salt films were obtained with different surface morphologies (spherical and directional), and the presence of the imidazolium salt in the surface was confirmed. These films with different concentrations of the imidazolium salts C16MImCl and C16MImMeS presented antibiofilm activity against isolates of Candida tropicalis, Candida parapsilosis, and Candida albicans. The minor antibiofilm concentration assay enabled one to determine that an increasing imidazolium salt content promoted, in general, an increase in the inhibition percentage of biofilm formation. Scanning electron microscopy micrographs confirmed the effective prevention of biofilm formation on the imidazolium salt containing biomaterials. Lower concentrations of the imidazolium salts showed no cytotoxicity, and the poly(l-lactide)-imidazolium salt films presented good cell adhesion and proliferation percentages with human mesenchymal stem cells. Furthermore, no acute microscopic lesions were identified in the histopathological evaluation after contact between the films and pig ear skin. In combination with the good morphological, physicochemical, and mechanical properties, these poly(l-lactide)-based materials with imidazolium salt additives can be considered as promising biomaterials for use in the manufacturing of medical devices.

Simultaneous determination of epinephrine and dopamine by electrochemical reduction on the hybrid material SiO₂/graphene oxide decorated with Ag nanoparticles

This paper describes the synthesis, characterization and applications of a new hybrid material composed of mesoporous silica (SiO2) modified with graphene oxide (GO), SiO2/GO, obtained by the sol-gel process using HF as the catalyst. The hybrid material, SiO2/GO, was decorated with silver nanoparticles (AgNPs) with a size of less than 20 nanometres, prepared directly on the surface of the material using N,N-dimethylformamide (DMF) as the reducing agent. The resulting material was designated as AgNP/SiO2/GO. The Ag/SiO2/GO material was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and high-resolution transmission electron microscopy (HR-TEM). A glassy carbon electrode modified with AgNP/SiO2/GO was used in the development of a sensitive electrochemical sensor for the simultaneous determination of epinephrine and dopamine employing electrocatalytic reduction using squarewave voltammetry. Well-defined and separate reduction peaks were observed in PBS buffer at pH 7. No significant interference was seen for primarily biological interferents such as uric acid and ascorbic acid in the detection of dopamine and epinephrine. Our study demonstrated that the resultant AgNP/SiO2/GO-modified electrode is highly sensitive for the simultaneous determination of dopamine and epinephrine, with the limits of detection being 0.26 and 0.27 μmol L(-1), respectively. The AgNP/SiO2/GO-modified electrode is highly selective and can be used to detect dopamine and epinephrine in a human urine sample.

Self-assembly of NiTPP on Cu(111): a transition from disordered 1D wires to 2D chiral domains

The growth mechanism of NiTPP on Cu(111): from disordered 1D wires to self-assembled chiral domains.

Predicting carotid artery disease and plaque instability from cell-derived microparticles

OBJECTIVES

Cell-derived microparticles (MPs) are small plasma membrane-derived vesicles shed from circulating blood cells and may act as novel biomarkers of vascular disease. We investigated the potential of circulating MPs to predict (a) carotid plaque instability and (b) the presence of advanced carotid disease.

METHODS

This pilot study recruited carotid disease patients (aged 69.3 ± 1.2 years [mean ± SD], 69% male, 90% symptomatic) undergoing endarterectomy (n = 42) and age- and sex-matched controls (n = 73). Plaques were classified as stable (n = 25) or unstable (n = 16) post surgery using immunohistochemistry. Blood samples were analysed for MP subsets and molecular biomarkers. Odds ratios (OR) are expressed per standard deviation biomarker increase.

RESULTS

Endothelial MP (EMP) subsets, but not any vascular, inflammatory, or proteolytic molecular biomarker, were higher (p < .05) in the unstable than the stable plaque patients. The area under the receiver operator characteristic curve for CD31(+)41(-) EMP in discriminating an unstable plaque was 0.73 (0.56-0.90, p < .05). CD31(+)41(-) EMP predicted plaque instability (OR = 2.19, 1.08-4.46, p < .05) and remained significant in a multivariable model that included transient ischaemic attack symptom status. Annexin V(+) MP, platelet MP (PMP) subsets, and C-reactive protein were higher (p < .05) in cases than controls. Annexin V(+) MP (OR = 3.15, 1.49-6.68), soluble vascular cell adhesion molecule-1 (OR = 1.64, 1.03-2.59), and previous smoking history (OR = 3.82, 1.38-10.60) independently (p < .05) predicted the presence of carotid disease in a multivariable model.

CONCLUSIONS

EMP may have utility in predicting plaque instability in carotid patients and annexin V(+) MPs may predict the presence of advanced carotid disease in aging populations, independent of established biomarkers.

The atomic structure of a bare buffer layer on SiC(0001) chemically resolved

A chemical-specific photoelectron diffraction structure determination of a carbon rich buffer layer on SiC is reported.

Electronic and structural study of Pt-modified Au vicinal surfaces: a model system for Pt–Au catalysts

Morphology and electronic properties of Pt nanostructures are influenced by the underlying Au surface orientation and surface alloy formation, respectively.

Sol-gel thin-film based mesoporous silica and carbon nanotubes for the determination of dopamine, uric acid and paracetamol in urine

This work describes the preparation, characterization and application of a hybrid material composed of disordered mesoporous silica (SiO2) modified with multiwalled carbon nanotubes (MWCNTs), obtained by the sol-gel process using HF as the catalyst. This hybrid material was characterized by N2 adsorption-desorption isotherms, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission microscopy (HR-TEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). This new hybrid material was used for the construction of a thin film on a glassy carbon electrode. The modified electrode using this material was designated SiO2/MWCNT/GCE. The electrocatalytic properties of the electrode toward dopamine, uric acid and paracetamol oxidation were studied by differential pulse voltammetry. Well-defined and separated oxidation peaks were observed in phosphate buffer solution at pH 7.0, in contrast with the ill-defined peaks observed with unmodified glassy carbon electrodes. The electrode had high sensitivity for the determination of dopamine, uric acid and paracetamol, with the limits of detection obtained using statistical methods, at 0.014, 0.068 and 0.098 µmol L(-1), respectively. The electrode presented some important advantages, including enhanced physical rigidity, surface renewability by polishing and high sensitivity, allowing the simultaneous determination of these three analytes in a human urine sample.