We synthesized cubic nanoassemblies of octahedral CeO(2) nanocrystals by simply heating an aqueous solution of cerium nitrate (Ce(NO(3))(3)) in the presence of hexanedioic acid (HOOC(CH(2))(4)COOH) in a lab-scale plug-flow reactor. It was concluded that the octahedral shape of the primary CeO(2) nanocrystals plausibly leads to octa-coordination of the primary nanocrystals, thus enabling controlled assembly to form a cubic structure.

The effects of alginate/carboxyl methylcellulose composite coating incorporated with clove essential oil on quality of silver carp fillet chilled storage (4 + 1 °C) were examined over a period of 16 days. The control samples (c), alginate/carboxyl methylcellulose coating (C-A), alginate/carboxyl methylcellulose composite coating incorporated with clove essential oil (with different concentration 1 and 1.5 %) (C-A + CEOCEO 15 % respectively) were analyzed by bacteriological (total viable counts (TVC) and total psychrotrophic counts (TPC)), biochemical (Peroxide value (PV), free fatty acid (FFA), total volatile base nitrogen (TVB-N), and pH) and sensory characteristics. Also, the efficacy of these treatments was investigated in control of the population of Eschershia coli O157:H7 inoculated in silver carp fillet. According to the obtained results, C-A + CEO 1.5 % showed lowest (p < 0.05) and acceptable biochemical, bacteriological and sensory characteristics attributes up to 16 days storage at 4 °C compared to the others. Also, this treated sample was acceptable even at the end of the 16-day storage and it could reduce the population of E. coli O157:H7 below the acceptable level (<2) from day 4 until the end of the storage period. The results indicate Alginate/carboxyl methylcellulose composite coating with clove essential oil might be recommended as a preservative in the meat products.

The Cleveland Clinic has long had a reputation for medical excellence. But in 2009 the CEO acknowledged that patients did not think much of their experience there and decided to act. Since then the Clinic has leaped to the top tier of patient-satisfaction surveys, and it now draws hospital executives from around the world who want to study its practices. The Clinic's journey also holds Lessons for organizations outside health care that must suddenly compete by creating a superior customer experience. The authors, one of whom was critical to steering the hospital's transformation, detail the processes that allowed the Clinic to excel at patient satisfaction without jeopardizing its traditional strengths. Hospital leaders: Publicized the problem internally. Seeing the hospital's dismal service scores shocked employees into recognizing that serious flaws existed. Worked to understand patients' needs. Management commissioned studies to get at the root causes of dissatisfaction. Made everyone a caregiver. An enterprisewide program trained everyone, from physicians to janitors, to put the patient first. Increased employee engagement. The Clinic instituted a "caregiver celebration" program and redoubled other motivational efforts. Established new processes. For example, any patient, for any reason, can now make a same-day appointment with a single call. Set patients' expectations. Printed and online materials educate patients about their stays--before they're admitted. Operating a truly patient-centered organization, the authors conclude, isn't a program; it's a way of life.

The metabolism of aerobic life uses the conversion of molecular oxygen to water as an energy source. This reaction is catalyzed by cytochrome e oxidase (CeO) consuming four electrons and four protons, which move along specific routes. While all four electrons are transferred via the same cofactors to the binuclear reaction center (BNC), the protons take two different routes in the A-type CeO, i.e., two of the four chemical protons consumed in the reaction arrive via the D-channel in the oxidative first half starting after oxygen binding. The other two chemical protons enter via the K-channel in the reductive second half of the reaction cycle. To date, the mechanism behind these separate proton transport pathways has not been understood. In this study, we propose a model that can explain the reaction-step specific opening and closing of the K-channel by conformational and pKA changes of its central lysine 362. Molecular dynamics simulations reveal an upward movement of Lys362 towards the BNC, which had already been supposed by several experimental studies. Redox state-dependent pKA calculations provide evidence that Lys362 may protonate transiently, thereby opening the K-channel only in the reductive second half of the reaction cycle. From our results, we develop a model that assigns a key role to Lys362 in the proton gating between the two proton input channels of the A-type CeO.

Nanoporous cerium oxide (CeO(2)) thin film deposited onto platinum (Pt) coated glass plate using pulsed laser deposition (PLD) has been utilized for immobilization of glucose oxidase (GOx). Atomic force microscopy studies reveal the formation of nanoporous surface morphology of CeO(2) thin film. Response studies carried out using differential pulsed voltammetry (DPV) and optical measurements show that the GOx/CeO(2)/Pt bio-electrode shows linearity in the range of 25-300 mg/dl of glucose concentration. The low value of Michaelis-Menten constant (1.01 mM) indicates enhanced enzyme affinity of GOx to glucose. The observed results show promising application of the nanoporous CeO(2) thin film for glucose sensing application without any surface functionalization or mediator.

Oxygen vacancies on ceria (CeO(2)) surfaces play a crucial role in catalytic applications, yet whether vacancies are at surface or subsurface sites on reduced CeO(2)(111), and whether vacancies agglomerate or repel each other, is still under discussion, with few and inconsistent experimental results. By combining density-functional theory (DFT) in the DFT+U (U is an effective onsite Coulomb interaction parameter) approach and statistical thermodynamics, we show that the energetically most stable near-surface oxygen vacancy structures for a broad range of vacancy concentrations, Θ (1/16 ≤ Θ ≤ 1 monolayer) have all vacancies at subsurface oxygen sites and predict that the thermodynamically stable phase for a wide range of reducing conditions is a (2 × 2) ordered subsurface vacancy structure (Θ = 1/4). Vacancy-induced lattice relaxations effects are crucial for the interpretation of the repulsive interactions, which are at the basis of the vacancy spacing in the (2 × 2) structure. The findings provide theoretical data to support the interpretation of the most recent experiments, bringing us closer to solving the debate.

CeO2 nanoparticles (NPs) with average particle size of ∼17 nm were grown on graphene sheets by simply mixing cerium chloride as the Ce precursor with graphene oxide (GO) in distilled water and the simultaneous reduction of GO to reduced graphene oxide (rGO), followed by a one-step hydrothermal treatment at 150 °C. A unique blue to green tuneable luminescence was observed as a function of the excitation wavelength. With this method, significant applications of rGO-CeO2 nanocomposites in many optical devices could be realized. The photocatalytic activity of the as-synthesized CeO2 and rGO-CeO2 nanocomposite was investigated by monitoring the degradation of methylene blue (MB) dye under direct sunlight irradiation. The rGO-CeO2 nanocomposite exhibited excellent photocatalytic activity compared to CeO2 NPs by degrading 90% of the MB dye in 10 min irradiation under sunlight. This property of rGO-CeO2 nanocomposites was ascribed to the significant suppression of the recombination rate of photo-generated electron-hole pairs due to charge transfer between rGO sheets and CeO2 NPs and the smaller optical band-gap in the rGO-CeO2 nanocomposite.

Low penetration depth of excited light, undesirable distribution of photosensitizers, severe hypoxia, and inefficient reactive oxygen species (ROS) generation in tumors, lead to the poor therapeutic effects in photodynamic therapy. Herein, a multifunctional nanocluster bomb (UCGM naonoparticles) composed of upconversion nanoparticles (NPs), CeO_x , graphite-C₃ N₄ (g-C₃ N₄ ) NPs, and metformin (Met) are developed to mitigate the hypoxia by oxidizing H₂ O₂ into O₂ due to the catalysis of CeO_x . The presence of Met can act on the mitochondrion to inhibit the respiration of tumor cells, further improving the O₂ level. Meanwhile, g-C₃ N₄ NPs are released from UCGM NPs and penetrate tumor tissue deeply because of their small size. Upon 808 nm laser illumination, UCGM NPs show remarkable photothermal ability and efficiently convert near infrared to ultraviolet light to activate the g-C₃ N₄ NPs to generate ROS in a whole tumor to facilitate a combined antitumor effect against deeply located tumors. Moreover, these UCGM NPs also display excellent performances in upconversion luminescence, magnetic resonance imaging, and computerized tomographic imaging, making them a potential imaging-guided drug delivery system in cancer therapy.

Pt-CeO(x) nanowire (NW)/C electrocatalysts for the improvement of oxygen reduction reaction (ORR) activity on Pt were prepared by a combined process involving precipitation and coimpregnation. A low, 5 wt % Pt-loaded CeO(x) NW/C electrocatalyst, pretreated by an optimized electrochemical conditioning process, exhibited high ORR activity over a commercially available 20 wt % Pt/C electrocatalyst although the ORR activity observed for a 5 wt % Pt-loaded CeO(x) nanoparticle (NP)/C was similar to that of 20 wt % Pt/C. To investigate the role of a CeO(x) NW promotor on the enhancement of ORR activity on Pt, the Pt-CeO(x) NW interface was characterized by using hard X-ray photoelectron spectroscopy (HXPS), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). Microanalytical data obtained by these methods were discussed in relation to atomistic simulation performed on the interface structures. The combined techniques of HXPS, TEM-EELS, and atomistic simulation indicate that the Pt-CeO(x) NW interface in the electrocatalyst contains two different defect clusters: Frenkel defect clusters (i.e., 2Pt(i)(••) - 4O(i)″ - 4V(o)(••) - V(Ce)″″) formed in the surface around the Pt-CeO(x) NW interface and Schottky defect clusters (i.e., (Pt(Ce)″ - 2V(O)(••) - 2Ce(Ce)') and (Pt(Ce)″ - V(O)(••))) which appear in the bulk of the Pt-CeO(x) NW interface similarly to Pt-CeO(x) NP/C. It is concluded that the formation of both Frenkel defect clusters and Schottky defect clusters at the Pt-CeO(x) NW heterointerface contributes to the promotion of ORR activity and permits the use of lower Pt-loadings in these electrocatalysts.

A very small number of biomaterials investigated for bone regeneration were reported as able to prevent the oxidative stress. In this study beads based on alginate hydrogel and mesoporous glasses (MG) containing different amounts of cerium oxides (Ce³⁺/Ce⁴⁺) exhibiting antioxidant properties were investigated as a good approach to mimic the action of antioxidant enzymes in our organism. The effect of cerium contents on the bioactivity and biocompatibility of beads were investigated. Moreover, the potential capability of Ce-containing MG to prevent the oxidative stress caused by the activity of reactive oxygen species (ROS) was here investigated for the first time. The increment of cerium oxide from 1.2, to 3.6 and 5.3 mol% decreases the surface area and porosity of MG and increases the catalase mimetic activity after 168 h. Swelling tests in different cell culture media (D- and α-MEM) demonstrated the rehydration capability of beads. The presence of beads with the highest Ce-contents (3.6 and 5.3%) improved the proliferation of pre-osteoblastic cells MC3T3-C1 cells. However, the cell differentiation decreased when increased the cerium content. Lactate dehydrogenase assays showed beads are cytocompatible materials. Moreover, oxidative stress tests with H₂O₂ showed a better response related to cell viability and the elimination of oxidant species when increased cerium content. Beads of glasses with 1.2 and 3.6% of CeO₂ are excellent candidates as bioactive scaffolds for bone regeneration capable of counteract the oxidative stress.

BACKGROUND

It is well known that Cymbopogon (lemon grass) essential oil exhibits antimicrobial activity while the efficacy of silver ions as a disinfectant is equally well reported.

OBJECTIVE

The antimicrobial activity of CEO and Ag(+) and their synergistic combinations will be useful in improving the current treatment strategies for various infections.

METHODS

In the present study, we determined the chemical composition and in vitro antimicrobial activity of six different Cymbopogon essential oils (CEO's) alone and in combination with silver ions (Ag(+)) against two Gram-positive (Staphylococcus aureus and Enterococcus faecalis), two Gram-negative (Escherichia coli and Moraxella catarrhalis) and two yeast species (Candida albicans and Candida tropicalis). The nature of potential interactions was determined by fractional inhibitory concentration indices (FICIs) for CEO's and Ag(+) calculated from microdilution assays and time-kill curves.

RESULTS

Gas chromatography-mass spectrometry results confirmed the presence of nerol, geranial and geraniol as major volatile compounds. Minimum inhibitory concentration (MIC) values confirmed that all the tested pathogens are variably susceptible to both CEO's as well as Ag(+). The MIC of CEO's and Ag(+) against all the tested pathogens ranged from 0.032 mg/ml to 1 mg/ml and 0.004 and 0.064 mg/ml respectively, whereas when assayed in combination the FICI values were drastically reduced to range between 0.258 and 2.186, indicating synergy, additive and indifferent interactions. The most prominent interaction was observed between Cymbopogon flexuosus essential oil and Ag(+) against C. albicans with ∑FIC = 0.254. The synergistic interactions were further confirmed through the construction of isobolograms and time-kill plots. Transmission electron microscopy showed disturbance in the cell envelope upon the concomitant treatment of CEO's and Ag(+), which ultimately leads to cell death.

CONCLUSIONS

Results suggest that CEO's and Ag(+) when used in combination offers an opportunity to the formulation scientist to produce novel combinations acting synergistically in the continued quest to control important infectious pathogens.

Three patients had residual or recurrent tumour following excision of large ocular surface squamous neoplasia (OSSN) lesions, which did not resolve despite the use of adjunctive cryotherapy and topical mitomycin-C therapy. The residual tumour was treated with topical or subconjunctival injectable interferon alpha 2b. All three eyes had complete resolution of the OSSN lesions after an average of 6 weeks (range 4-8 weeks) of treatment with interferon alpha 2b. No regrowth was seen during the follow-up period of 22.7 +/- 32.3 months (range 5-60 months). No adverse reactions or complaints were reported during and following interferon use, and previous symptoms from mitomycin-C treatment resolved completely. In these patients subconjunctival or topical interferon was an effective and safe treatment for residual OSSN. Longer follow up is required to confirm the long-term efficacy in prevention of recurrences.

Many common management practices in healthcare organizations, including the practice of strategic planning, have not been subject to widespread assessment through empirical research. If management practice is to be evidence-based, evaluations of such common practices need to be undertaken. The purpose of this research is to provide evidence on the extent of strategic planning practices and the association between hospital strategic planning processes and financial performance. In 2006, we surveyed a sample of 138 chief executive officers (CEOs) of hospitals in the state of Texas about strategic planning in their organizations and collected financial information on the hospitals for 2003. Among the sample hospitals, 87 percent reported having a strategic plan, and most reported that they followed a variety of common practices recommended for strategic planning-having a comprehensive plan, involving physicians, involving the board, and implementing the plan. About one-half of the hospitals assigned responsibility for the plan to the CEO. We tested the association between these planning characteristics in 2006 and two measures of financial performance for 2003. Three dimensions of the strategic planning process--having a strategic plan, assigning the CEO responsibility for the plan, and involving the board--are positively associated with earlier financial performance. Further longitudinal studies are needed to evaluate the cause-and-effect relationship between planning and performance.

BACKGROUND

In an era of increasing healthcare costs, the number and value of nonclinical workers, especially hospital management, has come under increased study. Compensation of hospital executives, especially at major nonprofit medical centers, and the "wage gap" with physicians and clinical staff has been highlighted in the national news. To our knowledge, a systematic analysis of this wage gap and its importance has not been investigated.

OBJECTIVE

(1) How do wage trends compare between physicians and executives at major nonprofit medical centers? (2) What are the national trends in the wages and the number of nonclinical workers in the healthcare industry? (3) What do nonclinical workers contribute to the growth in national cost of healthcare wages? (4) How much do wages contribute to the growth of national healthcare costs? (5) What are the trends in healthcare utilization?

METHODS

We identified chief executive officer (CEO) compensation and chief financial officer (CFO) compensation at 22 major US nonprofit medical centers, which were selected from the US News & World Report 2016-2017 Hospital Honor Roll list and four health systems with notable orthopaedic departments, using publicly available Internal Revenue Service 990 forms for the years 2005, 2010, and 2015. Trends in executive compensation over time were assessed using Pearson product-moment correlation tests. As institution-specific compensation data is not available, national mean compensation of orthopaedic surgeons, pediatricians, and registered nurses was used as a surrogate. We chose orthopaedic surgeons and pediatricians for analysis because they represent the two ends of the physician-compensation spectrum. US healthcare industry worker numbers and wages from 2005 to 2015 were obtained from the Bureau of Labor Statistics and used to calculate the national cost of healthcare wages. Healthcare utilization trends were assessed using data from the Agency for Healthcare Quality and Research, the National Ambulatory Medical Care Survey, and the National Hospital Ambulatory Medical Care Survey. All data were adjusted for inflation based on 2015 Consumer Price Index.

RESULTS

From 2005 to 2015, the mean major nonprofit medical center CEO compensation increased from USD 1.6 ± 0.9 million to USD 3.1 ± 1.7 million, or a 93% increase (R = 0.112; p = 0.009). The wage gap increased from 3:1 to 5:1 with orthopaedic surgeons, from 7:1 to 12:1 with pediatricians, and from 23:1 to 44:1 with registered nurses. We saw a similar wage-gap trend in CFO compensation. From 2005 to 2015, mean healthcare worker wages increased 8%. Management worker wages increased 14%, nonclinical worker wages increased 7%, and physician salaries increased 10%. The number of healthcare workers rose 20%, from 13 million to 15 million. Management workers accounted for 3% of this growth, nonclinical workers accounted for 27%, and physicians accounted for 5% of the growth. From 2005 to 2015, the national cost-burden of healthcare worker wages grew from USD 663 billion to USD 865 billion (a 30% increase). Nonclinical workers accounted for 27% of this growth, management workers accounted for 7%, and physicians accounted for 18%. In 2015, there were 10 nonclinical workers for every one physician. The cost of healthcare worker wages accounted for 27% of the growth in national healthcare expenditures. From 2005 to 2015, the number of inpatient stays decreased from 38 million to 36 million (a 5% decrease), the number of physician office visits increased from 964 million to 991 million (a 3% increase), and the number of emergency department visits increased from 115 million to 137 million (a 19% increase).

CONCLUSIONS

There is a fast-rising wage gap between the top executives of major nonprofit centers and physicians that reflects the substantial, and growing, cost of nonclinical worker wages to the US healthcare system. However, there does not appear to be a proportionate increase in healthcare utilization. These findings suggest a growing, substantial burden of nonclinical tasks in healthcare. Methods to reduce nonclinical work in healthcare may result in important cost-savings.

UNASSIGNED

IV, economic and decision analysis.

The need for specificity and sensitivity in the analysis of DNA adducts has led the development of GC/MS methods. Such methods require chemical derivatization (i.e. silylation, electrophore labelling), which can also bring its own sets of problems, including the production of artifacts, interferences and sample to sample variability in derivatization. To obviate such problems, a liquid chromatographic/electrospray ionization mass spectrometric (LC/ESI-MS) method was developed to quantify N2,3-ethenoguanine (epsilon Gua), a promutagenic DNA adduct of vinyl chloride exposure. The response of epsilon Gua to isotopically labelled internal standard [13C4]epsilon Gua was linear (r2 = 0.999) and reproducible from 0.027 to 0.538 pmol microliter-1. We obtained an accuracy of 86 +/- 14% by analyzing chloroethylene oxide (CEO)-treated calf thymus DNA enriched with authentic epsilon Gua. The analysis of CEO-treated calf thymus DNA samples not enriched with authentic epsilon Gua provided a precision of 15%. The detection limits with a signal-to-noise ratio (S/N) 2.5:1 were obtained in the determination of authentic epsilon Gua at 5 fmol per injection. The detection limit obtained in the routine analysis of the biological samples was 50 fmol epsilon Gua with S/N = 3:1. The applicability of the method was established by determining epsilon Gua in rats treated with CEO by portal vein injection and an unexposed human liver. It was observed that the concentration of epsilon Gua in the rat livers increased with increase in dose and was inversely related to the time after, CEO exposure. This trend suggests rapid repair of the adduct in rat livers. In the human liver DNA sample, epsilon Gua was quantitated at 0.06 +/- 0.01 pmol mg-1 DNA.

The effect of the suppport on oxidative dehydrogenation activity for vanadia/ceria systems is examined for the oxidation of methanol to formaldehyde by use of well-defined VO(x)/CeO(2)(111) model catalysts. Temperature-programmed desorption at low vanadia loadings revealed reactivity at much lower temperature (370 K) as compared to pure ceria and vanadia on inert supports such as silica. Density functional theory is applied and the energies of hydrogenation and oxygen vacancy formation also predict an enhanced reactivity of the vanadia/ceria system. At the origin of this support effect is the ability of ceria to stabilize reduced states by accommodating electrons in localized f-states.

The structural and electronic properties of Ce(1-x)Cu(x)O(2) nano systems prepared by a reverse microemulsion method were characterized with synchrotron-based X-ray diffraction, X-ray absorption spectroscopy, Raman spectroscopy, and density functional calculations. The Cu atoms embedded in ceria had an oxidation state higher than those of the cations in Cu(2)O or CuO. The lattice of the Ce(1)(-x)Cu(x)O(2) systems still adopted a fluorite-type structure, but it was highly distorted with multiple cation-oxygen distances with respect to the single cation-oxygen bond distance seen in pure ceria. The doping of CeO(2) with copper introduced a large strain into the oxide lattice and favored the formation of O vacancies, leading to a Ce(1-x)Cu(x)O(2-y) stoichiometry for our materials. Cu approached the planar geometry characteristic of Cu(II) oxides, but with a strongly perturbed local order. The chemical activities of the Ce(1-x)Cu(x)O(2) nanoparticles were tested using the reactions with H(2) and O(2) as probes. During the reduction in hydrogen, an induction time was observed and became shorter after raising the reaction temperature. The fraction of copper that could be reduced in the Ce(1-x)Cu(x)O(2) oxides also depended strongly on the reaction temperature. A comparison with data for the reduction of pure copper oxides indicated that the copper embedded in ceria was much more difficult to reduce. The reduction of the Ce(1-x)Cu(x)O(2) nanoparticles was rather reversible, without the generation of a significant amount of CuO or Cu(2)O phases during reoxidation. This reversible process demonstrates the unusual structural and chemical properties of the Cu-doped ceria materials.

OBJECTIVE

To analyse the pattern of change in publication content and citations generated by a mid-ranking ophthalmology journal as it evolved from the Australian and New Zealand Journal of Ophthalmology (ANZJO) to its successor, Clinical 0mp; Experimental Ophthalmology (CEO).

METHODS

The Science Citation Index was used to analyse the publications of ANZJO and CEO over two 10-year periods (1990-1999 and 2000-2009, respectively). Publication and citation patterns were analysed in terms of source authors, institutions and countries. As a secondary measure, journal impact factors (JIFs) were retrieved from the Journal Citation Reports at the end of each period.

RESULTS

Over the specified periods, 859 articles published in ANZJO were cited 1210 times, and 1529 articles published in CEO were cited 5374 times. Australia was the largest contributing country to both journals; however, the proportional contributions from other countries including New Zealand, UK, USA, India and China increased significantly in CEO. Articles were cited by authors from 793 institutions in 60 countries for ANZJO and 2997 institutions in 95 countries for CEO. The contribution by key authors (identified as the top 10 most-published authors) towards total journal publications was 24% in ANZJO, but only 16% in CEO; however, these publications were responsible for 26.6% and 28.8% of the total citations, respectively. With respect to the most recent JIFs, ANZJO was 0.433 in 1999 (ranked 33 of 43 journals) and CEO was 1.35 in 2008 (ranked 27 of 48 journals).

CONCLUSIONS

CEO has substantially increased the number of publications, citation counts and international sources compared with its well-established predecessor, ANZJO, over the assessed periods. CEO also appears to have a higher international profile with increasing citations counts from more countries. This evolution from a regional, to a more international, journal has been substantial and is reflected by a significant increment in JIF, and a modest increase in overall JIF-ranking, for CEO.

Medicinal plants contain various secondary metabolites. The present study analyzed the essential oil of buds from clove (Syzygium aromaticum L.; Family: Myrtaceae) using gas chromatography-mass spectrometry (GC-MS). GC-MS analysis showed the presence of six major phytoconstituents, such as eugenol (66.01%), caryophyllene (19.88%), caryophyllene oxide (5.80%), phenol, 2-methoxy-4-(2-propenyl)-acetate (4.55%), and humulene (3.75%). The effect of clove essential oils (CEO) at 0%, 1%, 2%, and 3% (w/w) on the mechanical and barrier properties of starch films was evaluated. The tensile strength (TS) and elongation (E) of films with clove essential oil were 6.25 ± 0.03 MPa and 5.67% ± 0.08%, respectively. The antioxidant activity of the films significantly increased the millet starch film and presented the lowest antioxidant activity (0.3%) at a 30 minute incubation for the control sample, while increasing CEO fraction in the starch film lead to an increase in antioxidant activity, and the 3% CEO combined film presented the highest antioxidant activity (15.96%) at 90 min incubation. This finding could be explained by the incorporation of clove oil containing antioxidant properties that significantly increased with the incorporation of CEO (p < 0.05). A zone of inhibition ranging from 16 to 27 mm in diameter was obtained when using a concentration of CEO ranging from 1% to 3%. We also observed the presence of an antimicrobial activity on several tested microorganism including Escherichia coli, Pseudomonas aeruginosa, Enterobacter sp, Bacillus cereus, Staphylococcus aureus, and Trichoderma fungi. Thus, the current study reveals the possibility of using a millet starch edible film as a preservation method.

The ability to tune thin oxide coatings by wet-chemistry is desirable for many applications, yet it remains a key synthetic challenge. In this work, we introduce a general colloidal atomic layer deposition (c-ALD) synthesis to grow an alumina shell with tunable thickness around nanocrystalline cores of various compositions spanning from ionic semiconductors (i.e., CsPbX₃, with X = Br, I, Cl) to metal oxides and metals (i.e., CeO₂ and Ag). The distinctive characteristics of each core (i.e., emission, facile surface functionalization, stability) allowed us to optimize and to elucidate the chemistry of the c-ALD process. Compared to gas-phase ALD, this newly developed synthesis has the advantage of preserving the colloidal stability of the nanocrystalline core while controlling the shell thickness from 1 to 6 nm. As one example of the opportunities offered by the growth of a thin oxide shell, we study the anion exchange reaction in the CsPbX₃ perovskites nanocrystals by in situ X-ray diffraction, which had been impeded so far by the instability of this class of materials and by the fast exchange kinetics.

Density functional theory calculations that account for the on-site Coulomb interaction via a Hubbard term (DFT+U) reveal the mechanisms for the oxidation of CO catalyzed by isolated Au atoms as well as small clusters in Au/CeO(2) catalysts. Ceria (111) surfaces containing positively charged Au ions, either as supported Au(+) adatoms or as substitutional Au(3+) ions, are shown to activate molecular CO and to catalyze its oxidation to CO(2). In the case of supported single Au(+) adatoms, the limiting rate for the CO oxidation is determined by the adsorbate spillover from the adatom to the oxide support. The reaction then proceeds with the CO oxidation via lattice oxygen and O vacancy formation. These vacancies are shown to readily attract the supported Au(+) adatoms and to turn them into negatively charged Au(delta-) adspecies that deactivate the catalyst, preventing further CO adsorption. Au(3+) ions dispersed into the ceria lattice as substitutional point defects can instead sustain a full catalytic cycle consisting of three individual steps maintaining their activity along the reaction process: Au cations in Au(x)Ce(1-x)O(2) systems promote multiple oxidations of CO without any activation energy via formation of surface O vacancies. Molecular oxygen adsorbs at these vacancies and forms O adspecies that then catalyze the oxidation of molecular CO, closing the catalytic cycle and recovering the stoichiometric Au(x)Ce(1-x)O(2) system. The interplay between the reversible Ce(4+)/Ce(3+) and Au(3+)/Au(+) reductions underpins the high catalytic activity of dispersed Au atoms into the ceria substrate. It is shown that the positive oxidation state of the substitutional Au ions is retained along the catalytic cycle, thus preventing the deactivation of Au(x)Ce(1-x)O(2) catalysts in operation conditions. Finally, although a single Au(+) adatom bound to an O vacancy is shown to deactivate during CO oxidation, the calculations predict that the reactivity of gold nanoparticles nucleated at O vacancies can be recovered for cluster sizes as small as Au(2).

Ceria (CeO(2)) is a promising catalyst for the reduction of carbon dioxide (CO(2)) to liquid fuels and commodity chemicals, in part because of its high oxygen storage capacity, yet the fundamentals of CO(2) adsorption, activation, and reduction on ceria surfaces remain largely unknown. We use density functional theory, corrected for onsite Coulombic interactions (GGA+U), to explore various adsorption sites and configurations for CO(2) on stoichiometric and reduced ceria (110), the latter with either an in-plane oxygen vacancy or a split oxygen vacancy. We find that CO(2) adsorption on both reduced ceria (110) surfaces is thermodynamically favored over the corresponding adsorption on stoichiometric ceria (110), but the most stable adsorption configuration consists of CO(2) adsorbed parallel to the reduced ceria (110) surface at a split oxygen vacancy. Structural changes in the CO(2) molecule are also observed upon adsorption. At the split vacancy, the molecule bends out of plane to form a unidentate carbonate with the remaining oxygen anion at the surface; this is in stark contrast to the bridged carbonate observed for CO(2) adsorption at the in-plane vacancy. Also, we analyze the pathways for CO(2) conversion to CO on reduced ceria (110). The subtle difference in the energies of activation for the elementary steps suggest that CO(2) dissociation is favored on the split vacancy, while the reverse process of CO oxidation may favor the formation of the in-plane vacancy. We thus show how the structure and properties of the ceria catalyst govern the mechanism of CO(2) activation and reduction.

Cerium Oxide nanoparticles (CeO(2-x) NPs) are modified with polymer brushes of negatively charged poly (3-sulfopropylmethacrylate) (PSPM) and positively charged poly (2-(methacryloyloxy)ethyl-trimethylammonium chloride) (PMETAC) by Atom Transfer Radical Polymerisation (ATRP). CeO(2-x) NPs are fluorescently labelled by covalently attaching Alexa Fluor® 488/Fluorescein isothiocyanate to the NP surface prior to polymerisation. Cell uptake, intracellular distribution and the impact on the generation of intracellular Reactive Oxygen Species (ROS) with respect to CeO(2-x) NPs are studied by means of Raman Confocal Microscopy (CRM), Transmission Electron Microscopy (TEM) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). PSPM and PMETAC coated CeO(2-x) NPs show slower and less uptake compared to uncoated Brush modified NPs display a higher degree of co-localisation with cell endosomes and lysosomes after 24 h of incubation. They also show higher co-localisation with lipid bodies when compared to unmodified CeO(2-x) NPs. The brush coating does not prevent CeO(2-x) NPs from displaying antioxidant properties.