245 research outputs found
New Multifunctional Lanthanide and Zr(IV) Phosphonates Derived from the 5-(dihydroxyphosphoryl) Isophthalate Ligand as Proton Conductors
Metal phosphonates are essentially acidic solids featured by groups such as P-OH, -COOH, etc. Moreover, the presence of coordination and lattice water molecules favors the formation of H-bond networks, which make these compounds appropriate as proton conductors, attractive for proton exchange membranes (PEMs) of fuel Cells.1
We report here, general characteristics of metal phosphonate derivatives composed of the polyfunctional 5-(dihydroxyphosphoryl) isophthalate ligand2 and lanthanides or zirconium ions. In the case of the lanthanide derivatives, crystalline compounds were synthesized under hydrothermal conditions. Preliminary results suggest that at least three isostructural series of compounds are formed. One of them, with La3+ derivative as prototype, is characterized by an orthorhombic unit cell (a = 12.7745(6) Å, b = 11.8921(4) Å, c = 7.2193(5) Å). Pr3+, Eu3+ and Gd3+ compounds, displays a monoclinic unit cell likewise the Yb3+ solid, the latter exhibiting different crystallographic parameters. Zr(IV) = compound, with formula Zr[(HO3P-C6H3-(COO)2H)2]·8H2O; was obtained at 80 ºC in the presence of HF as mineralizing agent. This solid crystallizes in an orthorhombic unit cell (a = 21.9306 Å, b = 16.6169 Å, c = 3.6462 Å). All these compounds contain in their frameworks water molecules that contribute to the formation of H-bond networks, making them prone as proton conductor candidates. Structural and proton conductivity are underway.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Plan Propio de Investigación de la UMA
MAT2016-77648
Synthesis and Structural Characterization of a Tetranuclear Zinc(II) Complex with P,P'-Diphenylmethylenediphosphinate (pcp) and 2,2'-Bipyridine (2,2'-bipy) Ligands
A new tetranuclear complex of zinc(II) with P,P′-diphenylmethylenediphosphinate and 2,2′- bipyridine ligands was synthesized. [(pcp)(2,2′-bipy)Zn (μ3-pcp)Zn (2,2′-bipy)]2 · 6H2O was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and X-ray diffractometry. The structure consists of tetranuclear complexes connected through water hydrogen-bonding interactions in corrugated 2D layers. Two crystallographically independent zinc ions are in a distorted five-coordinate environment, being surrounded by three oxygen atoms of phosphinate groups (from two pcp ligands) and by two bipy nitrogen donors. Of the two independent pcp anions the first one utilizes all of its oxygen donors to coordinate one metal as bidentate and two metal atoms as a monodentate ligand, whereas the second one is only bidentate for one metal atom
A proposal for an evidence-based model of the screening for the colorectal carcinoma in an Italian setting
Introduction. The aim of this paper is to improve the feasibility perception of policymakers, health care workers and target population about the cost-effectiveness of the implementation of
colorectal screening as Public Health strategy.
Methods. Retrospective study by application of a three-step model designed for a local setting in Sicily (Palermo and its Province) in order to distribute Fecal Occult Blood Tests (FOBTs), offer
colonoscopy and surgery, by district allocation of pharmacies, public digestive endoscopic centres and oncologic and general surgery units. Mean adherence to consolidated colorectal screening programs in Italy was applied in order to evaluate the feasibility of an operative model in our area.
Results. Applying the model to the target population (269,368 individuals of both sexes), it can be expected a mean percentage of 79% delivered invitation and a mean participation rate
of 46.3% accounting for a total of 213,070 invited individuals and 98,651 participating in the first round of the program. Furthermore, considering the national mean of 6% positive FOBT,
82% of colonscopy adhesion and 7% CRC detection rate, it can be scheduled a burden for health care structures involved in the program accounting for 49,325 FOBTs, 2,338 colonscopies and
141 surgeries for each year.
Discussion. This work demonstrates the feasibility of a colorectal screening project in our area, showing a sustainable impact for local health care involved structures. Furthermore, this program
may be spread as an applicative model to other areas, adapting the project to the needs of the local setting in which the colorectal screening will be organized
Poor pathogenetic role of luminal obstruction in the development of appendicitis: A case report
Cellulose Nanocrystals and Lignin Nanoparticles Extraction from Lemna minor L.: Acid Hydrolysis of Bleached and Ionic Liquid-Treated Biomass
Using biomass to develop and obtain environmentally friendly and industrially applicable biomaterials is increasingly attracting global interest. Herein, cellulose nanocrystals (CNCs) and lignin nanoparticles (LNPs) were extracted from Lemna minor L., a freshwater free-floating aquatic species commonly called duckweed. To obtain CNCs and LNPs, two different procedures and biomass treatment processes based on bleaching or on the use of an ionic liquid composed of triethylammonium and sulfuric acid ([TEA][HSO4]), followed by acid hydrolysis, were carried out. Then, the effects of these treatments in terms of the thermal, morphological, and chemical properties of the CNCs and LNPs were assessed. The resulting nanostructured materials were characterized by using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that the two methodologies applied resulted in both CNCs and LNPs. However, the bleaching-based treatment produced CNCs with a rod-like shape, length of 100-300 nm and width in the range of 10-30 nm, and higher purity than those obtained with ILs that were spherical in shape. In contrast, regarding lignin, IL made it possible to obtain spherical nanoparticles, as in the case of the other treatment, but they were characterized by higher purity and thermal stability. In conclusion, this research highlights the possibility of obtaining nanostructured biopolymers from an invasive aquatic species that is largely available in nature and how it is possible, by modifying experimental procedures, to obtain nanomaterials with different morphological, purity, and thermal resistance characteristics
Hydrothermal synthesis of (C5H14N2)[CoCl4]⸳0.5H2O: Crystal structure, spectroscopic characterization, thermal behavior, magnetic properties and biological evaluation
The organic-inorganic compound (C5H14N2)[CoCl4]⸳0.5H2O, I, was characterized by various physicochemical techniques. The X-ray diffraction analysis revealed that the compound crystallizes in the centrosymmetric space group C2/c of the monoclinic system. The atomic arrangement the Co(II) complex is built from isolated [CoCl4]2– anions, 1-methylpiperazine-1,4-diium [C5H14N2]2+ cations and free water molecules. The crystal structure study showed that the cohesion of I is assured through N–H···Cl and N–H···O hydrogen bonds giving birth to a 3-D architecture. Hirshfeld surface analysis revealed that Cl···H/H···Cl and H···H (58.5 and 36.4%, respectively) are the most significant interactions between species. Minor O···H/H···O interactions are also present. The compound was characterized by thermal analysis, TGA-DTA showed the removal of the co-crystallized water before 100 °C and a first mass loss at around 120 °C. Magnetic measurements are in good agreement with isolated, S = 3/2, tetrahedral [CoCl4]2− anions. The negative Weiss constant of -1.35 indicates single-ion anisotropy and very weak antiferromagnetic interactions. UV–visible spectroscopy reveals three weak absorption bands in the visible range due to the d-d electronic transitions typical of the Co(II) tetra-coordinated. A bioassay showed antibacterial activity against the gram negative Klebsiella pneumonia and gram positive Bacillus ceureus, Listeria monocytogenes, and Micrococcus lutues
Water-Based Synthesis and Enhanced CO2 Capture Performance of Perfluorinated Cerium-Based Metal–Organic Frameworks with UiO-66 and MIL-140 Topology
Reaction of cerium ammonium nitrate and tetrafluoroterephthalic acid in water afforded two new metal–organic frameworks with UiO-66 [F4_UiO-66(Ce)] and MIL-140 [F4_MIL-140A(Ce)] topologies. The two compounds can be obtained in the same experimental conditions, just by varying the amount of acetic acid used as crystallization modulator in the synthesis. Both F4_UiO-66(Ce) and F4_MIL-140A(Ce) feature pores with size <8 Å, which classifies them as ultramicroporous. Combination of X-ray photoelectron spectroscopy and magnetic susceptibility measurements revealed that both compounds contain a small amount of Ce(III), which is preferentially accumulated near the surface of the crystallites. The CO2 sorption properties of F4_UiO-66(Ce) and F4_MIL-140A(Ce) were investigated, finding that they perform better than their Zr-based analogues. F4_MIL-140A(Ce) displays an unusual S-shaped isotherm with steep uptake increase at pressure <0.2 bar at 298 K. This makes F4_MIL-140A(Ce) exceptionally selective for CO2 over N2: the calculated selectivity, according to the ideal adsorbed solution theory for a 0.15:0.85 mixture at 1 bar and 293 K, is higher than 1900, among the highest ever reported for metal–organic frameworks. The calculated isosteric heat of CO2 adsorption is in the range of 38–40 kJ mol–1, indicating a strong physisorptive character
Structural characterization of the of inorganic and organic hydrotalcites
Layered double hydroxides are versatile materials used for intercalating bioactive molecules, both in pharmaceutical and cosmetic fields, with the purpose of protecting them from degradation, enhancing their water solubility to increase bioavailability, and/or obtaining modified release properties. Hydrotalcite is commercially available in its carbonate form, which is usually transformed into the nitrate form and finally exchanged by organic anions to obtain or regulate bioactivity or photo-activity effects (1). In this study all the steps of these transformations were characterized from the structural viewpoints by X-ray powder diffraction (XRPD) and automated electron diffraction tomography (ADT). ADT allowed shedding light on the nitrate position and conformation inside LDH. XRPD demonstrated at first that the presence of carbonate impurities is able to drive the intercalation of organic molecules into LDH, since CO32- contaminated samples tend to assume d-spacings roughly multiple of LDH-CO3 d-spacing. Finally XRPD was employed at in situ conditions to unravel the structural transformation occurring during the substitution of carbonate by nitrate ion and of the nitrate ion by organic anions. The carbonate-nitrate substitutions resulted to be very rapid (only few seconds) and only the use of a fast area detector, coupled to synchrotron radiation, allowed obtaining reliable patterns to perform XRPD refinement of the disordered structure at the sub-second time resolution. The nitrate-organic substitution resulted slower and depending on the chemical properties of the organic molecules
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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