Bidimensional Inequalities with an Ordinal Variable

We investigate the normative foundations of two empirically implementable dominance criteria for comparing distributions of two attributes, where the first one is cardinal while the second is ordinal. The criteria we consider are Atkinson and Bourguignon\'s (1982) first quasi-ordering and a generalization of Bourguignon\'s (1989) ordered poverty gap criterion. In each case we specify the restrictions to be placed on the individual utility functions, which guarantee that all utility-inequality averse welfarist ethical observers will rank the distributions under comparison in the same way as the dominance criterion. We also identify the elementary inequality reducing transformations successive applications of which permit to derive the dominating distribution from the dominated one.Normative Analysis, Utilitarianism, Welfarism, Bidimensional Stochastic Dominance, Inequality Reducing Transformations

Hamiltonians separable in cartesian coordinates and third-order integrals of motion

We present in this article all Hamiltonian systems in E(2) that are separable in cartesian coordinates and that admit a third-order integral, both in quantum and in classical mechanics. Many of these superintegrable systems are new, and it is seen that there exists a relation between quantum superintegrable potentials, invariant solutions of the Korteweg-De Vries equation and the Painlev\'e transcendents.Comment: 19 pages, Will be published in J. Math. Phy

Room temperature Suzuki coupling of aryl iodides, bromides, and chlorides using a heterogeneous carbon nanotube-palladium nanohybrid catalyst

International audiencePalladium nanoparticles were immobilized on multi-walled carbon nanotubes by a layer-by-layer approach, resulting in a well-defined assembly. The nanohybrid was found effective in promoting Suzuki cross couplings of various halogenated aromatics, including chlorinated ones, with arylboronic acids under sustainable conditions. The heterogeneous catalyst could also easily be recovered from the reaction mixture and reused with no loss of activity over several cycles

Selective conversion of nitroarenes using a carbon nanotube-ruthenium nanohybrid

International audienceRuthenium nanoparticles were assembled on carbon nanotubes and the resulting nanohybrid was used in the hydrazine-mediated catalytic hydrogenation of various nitroarenes, at room temperature. Depending on the solvent, a selective transformation occurred, giving either access to the corresponding aniline or hydroxylamine derivative

Shunt dysfunction patterns after transjugular intrahepatic portosystemic shunt creation using a combination of a generic stent-graft and bare-stents.

Even though transjugular intrahepatic portosystemic shunt (TIPS) using Fluency Stent-grafts provides good shunt patency rates, shunt dysfunction is a great concern after TIPS creation, occurring in up to 20% of cases within one year. The objective of this study was to describe shunt dysfunction patterns after TIPS creation using a combination of generic stent-grafts/bare-stents. Single-center retrospective study of all TIPS revisions between January 2005 and December 2020. TIPS revision angiograms were analyzed for stents' positions, stenoses' diameters, and stenoses' locations. Out of 99 TIPS, a total of 33 TIPS revisions were included. The median time to TIPS revision was 10.4 months. Angiograms showed four patterns of TIPS dysfunction-associated features (DAF), defined as follows: Type 1 was defined as stenosis located after the stent end in the hepatic vein (HV), type 2 as intra-stent stenosis located in the hepatic vein, type 3 as intra-stent stenosis or a kink in the parenchymal tract or the portal vein end of the TIPS, and type 4 as a complete TIPS occlusion. Types 1, 2, 3, and 4 were seen in 23 (69.7%), 5 (15.2%), 2 (6.1%), and 3 (9.1%) TIPS respectively. TIPS revision was successful in 30 (90.1%) patients with median pre- and post-TIPS revision PSG of 18.5 mmHg and 8 mmHg respectively (p < .001). Our results illustrate the four angiographic patterns of TIPS DAF after TIPS creation using a combination of generic stent-grafts/bare-stents and emphasize the need for appropriate stent length extending to the HV/inferior vena cava junction

Mild and selective catalytic oxidation of organic substrates by a carbon nanotube-rhodium nanohybrid

International audienceA heterogeneous catalyst was assembled by stabilization of rhodium nanoparticles on carbon nanotubes. The nanohybrid was used for the catalytic aerobic oxidation of diverse substrates such as hydroquinones, hydroxylamines, silanes, hydrazines and thiols, at room temperature. The system proved very efficient on the investigated substrates and demonstrated high selectivity. The selective oxidation of organic compounds under mild conditions is of practical importance in synthetic chemistry. In addition to classical stoichiometric processes, catalytic systems have been devised to perform oxidation reactions. 1 Further improvements in terms of sustainability were also achieved by supporting the catalysts, thus allowing their reclaim and reuse. 2 Among the various catalyst supports, nanostructured carbon allotropes, in particular carbon nanotubes (CNTs), have emerged as highly promising platforms that provide unique advantages such as chemical, thermal, and mechanical stability in liquid media, inertness, high specific surface area, and chemically tunable topography. 3 We previously reported supramolecular assemblies of metallic nanoparticles (e.g. Au, Pd, Ru) on carbon nanotubes. These assemblies afforded metal-coated CNTs that were subsequently used in the heterogeneous catal-ysis of various organic transformations. 4 In the course of our investigations we demonstrated that CNTs acted as synergistic support capable of enhancing the performances of the catalytic metal. With these critical features in mind, we sought to expand the scope of our nanohybrid systems by developing a catalyst that would promote a broad scope of oxidation reactions under mild and sustainable conditions

Inductively Coupled Plasma-Atomic Emission Spectrometry for the Analysis of Heavy Metals and Arsenic in Tinctures

To ensure the safety of herbal medicinal products, particularly in liquid dosage forms, it is necessary to control environmental toxins to acceptable levels. However, there is no methodology for individual elemental impurities in tinctures. The aim of the study was to select sample preparation conditions for quantitative determination of heavy metals and arsenic in tinctures. Materials and methods: the study used tinctures of anomalous peony, motherwort and valerian sampled from pharmacies. Sample preparation involved microwave-assisted digestion of pre-concentrated aliquots. Quantitative determination of 16 elemental impurities (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sr, Ti, V, Zn, Hg) was carried out using inductively coupled plasma–atomic emission spectrometry. Results: according to the study results, quantitative analysis of most elemental impurities requires sample concentration at the preparation step. Due to the method sensitivity, direct quantification of individual elements in a sample is possible only at levels of not less than 0.1 mg/kg. The optimal volume of a tincture for concentration is 25 ml, both in terms of time efficiency and recovery of toxic elements. Conclusions: the proposed procedure showed the possibility of quantification of 16 elemental impurities in the tinctures. The concentrations of heavy metals and arsenic in the tinctures of anomalous peony, motherwort and valerian did not exceed 0.722 mg/kg. Zinc and manganese were the most abundant elemental impurities in the studied samples

The influence of perfusion solution on renal graft viability assessment

BACKGROUND: Kidneys from donors after cardiac or circulatory death are exposed to extended periods of both warm ischemia and intra-arterial cooling before organ recovery. Marshall’s hypertonic citrate (HOC) and Bretschneider’s histidine-tryptophan-ketoglutarate (HTK) preservation solutions are cheap, low viscosity preservation solutions used clinically for organ flushing. The aim of the present study was to evaluate the effects of these two solutions both on parameters used in clinical practice to assess organ viability prior to transplantation and histological evidence of ischemic injury after reperfusion. METHODS: Rodent kidneys were exposed to post-mortem warm ischemia, extended intra-arterial cooling (IAC) (up to 2 h) with preservation solution and reperfusion with either Krebs-Hensleit or whole blood in a transplant model. Control kidneys were either reperfused directly after retrieval or stored in 0.9% saline. Biochemical, immunological and histological parameters were assessed using glutathione-S-transferase (GST) enzymatic assays, polymerase chain reaction and mitochondrial electron microscopy respectively. Vascular function was assessed by supplementing the Krebs-Hensleit perfusion solution with phenylephrine to stimulate smooth muscle contraction followed by acetylcholine to trigger endothelial dependent relaxation. RESULTS: When compared with kidneys reperfused directly post mortem, 2 h of IAC significantly reduced smooth muscle contractile function, endothelial function and upregulated vascular cellular adhesion molecule type 1 (VCAM-1) independent of the preservation solution. However, GST release, vascular resistance, weight gain and histological mitochondrial injury were dependent on the preservation solution used. CONCLUSIONS: We conclude that initial machine perfusion viability tests, including ischemic vascular resistance and GST, are dependent on the perfusion solution used during in situ cooling. HTK-perfused kidneys will be heavier, have higher GST readings and yet reduced mitochondrial ischemic injury when compared with HOC-perfused kidneys. Clinicians should be aware of this when deciding which kidneys to transplant or discard

Fundamental limitations on "warp drive" spacetimes

"Warp drive" spacetimes are useful as "gedanken-experiments" that force us to confront the foundations of general relativity, and among other things, to precisely formulate the notion of "superluminal" communication. We verify the non-perturbative violation of the classical energy conditions of the Alcubierre and Natario warp drive spacetimes and apply linearized gravity to the weak-field warp drive, testing the energy conditions to first and second order of the non-relativistic warp-bubble velocity. We are primarily interested in a secondary feature of the warp drive that has not previously been remarked upon, if it could be built, the warp drive would be an example of a "reaction-less drive". For both the Alcubierre and Natario warp drives we find that the occurrence of significant energy condition violations is not just a high-speed effect, but that the violations persist even at arbitrarily low speeds. An interesting feature of this construction is that it is now meaningful to place a finite mass spaceship at the center of the warp bubble, and compare the warp field energy with the mass-energy of the spaceship. There is no hope of doing this in Alcubierre's original version of the warp-field, since by definition the point in the center of the warp bubble moves on a geodesic and is "massless". That is, in Alcubierre's original formalism and in the Natario formalism the spaceship is always treated as a test particle, while in the linearized theory we can treat the spaceship as a finite mass object. For both the Alcubierre and Natario warp drives we find that even at low speeds the net (negative) energy stored in the warp fields must be a significant fraction of the mass of the spaceship.Comment: 18 pages, Revtex4. V2: one reference added, some clarifying comments and discussion, no physics changes, accepted for publication in Classical and Quantum Gravit