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The cleavage of the C–N bonds of aromatic heterocycles, such as pyridines or quinolines, is a crucial step in the hydrodenitrogenation (HDN) industrial processes of fuels in order to minimize the emission of nitrogen oxides into the atmosphere. Due to the harsh conditions under which these reactions take place (high temperature and H2pressure), the mechanism by which they occur is only partially understood, and any study at the molecular level that reveals new mechanistic possibilities in this area is of great interest. Herein, we unravel the pyridine ring-opening mechanism of 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) ligands coordinated to the cis-{Re(CO)2(N-RIm)(PMe3)} (N-RIm= N-alkylimidazole) fragment under mild conditions. Computational calculations show that deprotonation of the pyridine ring, once dearomatized, is crucial to induce ring contraction, triggering extrusion of the nitrogen atom from the ring and cleavage of the C–N bond. It is noteworthy that different products (regioisomers) are obtained depending on whether the ligand used is bipy or phen due to the additional rigidity and stability conferred by the central ring of the phen ligand, an issue also addressed and clarified computationally. Strong support for the proposed mechanism is provided by the characterization and isolation, including three single-crystal X-ray diffraction structures, of several of the proposed reaction intermediates.

This paper proposes the use of the gain-changing non-linearity to improve the estimation of the ultimate point, which is used in many auto-tuning algorithm of PID controllers. The experiments for identification are similar to the relay feedback, therefore some well known advantages of this kind of experiments are maintained while the estimation error is significantly reduced. The identification method is evaluated with a batch of system dynamics, providing suitable results in all cases, which proves the validity of the approach.

In this work we analyze the stability regions for PI controllers under a Symmetric-Send-On-Delta sampling strategy. This event-based sampling provides a significant reduction in the data needed for control and certain immunity against noisy signals without affecting significantly the performance. Hitherto, most of the analysis of this kind of event-triggered strategies to determine the apparition of limit cycles are based on the Describing Function technique, which may provide misleading results. Instead, in this work the analysis is based on the Tsypkin’s margin, which provides accurate results. Through this robustness measure, the stability regions for PI controllers are obtained as a function of its parameters. Some well-known tuning rules are also evaluated to determine its stability.

This work evaluates the effect of applying osmodehydration (OD40 at atmospheric pressure) and pulsed-vacuum osmodehydration (ODVP40, at 498 mmHg) as pre-treatments before apple (cv. Granny Smith) drying. The pre-treatments were evaluated in terms of time-dependent free moisture content (MK), drying rates (DR), effective water diffusion (D), product shrinkage and color changes. The ODVP40 pre-treated samples (40 °Brix grape juice at 40 °C) had a higher total soluble solids content (p < 0.05) and lower moisture content (p < 0.05). Drying experiments were performed at three temperatures (50, 60, and 70 °C) and 3.5 m/s air-flow. Page model best fitted the MK (R2>0.996) and DR (R2>0.827). A response surface model was used to estimate the Page model parameters as a function of the initial sample's temperature (T) and total soluble solids concentration (SSo). D values (considering product shrinkage) were computed as 3.56–5.48 × 10−10m2/s, 6.86–14.35 × 10−10m2/s, 30.70–72.81×10–10m2/s for fresh, OD40 and ODVP40 apple, respectively.

ABSTRACTInflammation and oxidative stress are critical events involved in neurodegeneration. In animal models, it has been shown that chronic consumption of a hypercaloric diet, which leads to inflammatory processes, affects the hippocampus, a brain region fundamental for learning and memory processes. In addition, advanced age and menopause are risk factors for neurodegeneration. Hormone replacement therapy (HRT) ameliorates menopause symptoms. Tibolone (TB), a synthetic hormone, exerts estrogenic, progestogenic and androgenic effects on different tissues. We aimed to determine the effect of short-term TB administration on oxidative stress and inflammation markers in the hippocampus of ovariectomized rats fed a high-fat-and-fructose diet (HFFD). Adult female rats were ovariectomized (OVX) and fed standard diet or HFFD—consisting of 10% lard supplemented chow and 20% high-fructose syrup in the drinking water—and administered vehicle or TB (1 mg/kg for seven days). Finally, we administered hormone receptor antagonists (MPP, RU486 or FLU) to each of the OVX + HFFD + TB groups. Bodyweight, triglycerides and cholesterol, oxidative stress and inflammation markers, and the activity and expression of antioxidant enzymes were quantified in the hippocampus of each experimental group. We observed that short-term TB administration significantly reduced body weight, AGEs, MDA levels, increased SOD and GPx activity, improved GSH/GSSG ratio, and reduced IL-6 and TNF-α. Our findings suggest that short-term administration of TB decreases oxidative stress and reduces inflammation caused by HFFD and early estrogenic decline. These effects occurred via estrogen receptor alpha.

•La obesidad es una enfermedad frecuente, crónica, progresiva y recidivante que cursa con graves complicaciones y elevada mortalidad.•Cuando la obesidad está presente debemos actuar con tratamientos no farmacológicos y farmacológicos, que reduzcan el peso y las complicaciones de esta enfermedad.•Los fármacos basados en las incretinas asocian gran eficacia y seguridad para acordar con el paciente un plan terapéutico a largo plazo.•Con los datos actualmente disponibles sobre recuperación del peso al suprimir el tratamiento farmacológico de la obesidad, hace necesario mantener el tratamiento a largo plazo.

In this work, an auto-tuning method for PI controllers applied in a loop under a Symmetric-Send-On-Delta sampling strategy is proposed. Auto-tuning algorithms usually implement an identification phase to obtain some information about the system dynamic that is used for tuning the controller. In our proposal, two frequency response points are estimated through an iterative procedure. With this information, a simple tuning rule is applied which guarantees robustness against limit cycle oscillations that can be induced by the SSOD sampler. Both the robustness measure to limit cycles and the identification procedure are based on the describing function technique, whose validity in the networked control systems under study requires a low incidence of losing packets as well as the transmission delays to be known or negligible compared to the system's dynamic. Comparatives with other classical tuning rules support the suitability of the proposed method. The auto-tuning procedure has been validated through a simulation study reflecting its applicability for the most common dynamics found in industrial processes. [ABSTRACT FROM AUTHOR]

A new strategy for tuning the electronic properties of 1,2,3-triazol-5-ylidene metal complexes is reported using {Mo(η3-C4H7)(bipy)(CO)2} or {Re(bipy)(CO)3} fragments as substituents at the triazole N3 atom. The reaction of cationic molybdenum(II) and rhenium(I) 1-methyl-1,2,3-triazole compounds with the strong base KN(SiMe3)2in the presence of electrophilic metal fragments, such as AgOTf (OTf = trifluoromethanesufonate) or [CuCl(IPr)] [IPr = 2,6-(diisopropyl)phenylimidazol-2-ylidene] affords a new type of 1,2,3-triazol-5-ylidene complexes. For silver(I) cationic bis(triazolylidene), [Ag(tzNHCM)2]OTf (M = [Mo], 2; [Re], 4), complexes are obtained, whereas in the case of Cu(I) mixed normal/mesoionic NHC, [Cu(IPr)(tzNHCM)]OTf (M = [Mo], 7; [Re], 8) complexes are formed. This special type of mesoionic N-heterocyclic carbenes bear a metal fragment at the N3 atom of the 1,2,3-triazole moiety, showing notable enhancement of the carbene electron donor ability compared to conventional alkyl-substituted analogues. Transmetalation from cationic silver bis(triazolylidene) complexes 2and 4, prepared using this methodology, has proven to be very efficient toward [M′Cl(cod)]2(M′ = Rh, Ir; cod = 1,5-cyclooctadiene), affording the corresponding cationic bis(triazolylidene) [M′(cod)(tzNHCM)2]OTf (9–12) complexes. A subsequent reaction with CO(g) easily produces substitution of the diene ligand, affording the corresponding cis-dicarbonyl [M′(CO)2(tzNHCM)2]OTf (13–16) compounds.

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by impaired glucose homeostasis, insulin resistance and hyperglycemia. Among its serious multisystemic complications is diabetic retinopathy (DR), which develops slowly and often insidiously. This disorder—the most common cause of vision loss in working-age adults—is characterized by functional and morphological changes in the retina. It results from the exacerbation of ischemic and inflammatory conditions prompted by alterations in the blood vessels, such as the development of leukostasis, thickening of the basement membrane, retinal neovascularization and fibrovascular tissue formation at the vitreoretinal interface. The pathogenic alterations are usually triggered at the biochemical level, involving a greater activity in 4 pathways: the polyol pathway, the hexosamine pathway, the formation of advanced glycation end-products and the activation of protein kinase C isoforms. When acting together, these pathways give rise to increased levels of reactive oxygen species and decreased levels of endogenous antioxidant agents, thus generating oxidative stress. All current therapies are aimed at the later stages of DR, and their application implies side effects. One possible strategy for preventing the complications of DM is to counteract the elevated superoxide production stemming from a high level of blood glucose. Accordingly, some treatments are under study for their capacity to reduce vascular leakage and avoid retinal ischemia, retinal neovascularization and macular edema. The present review summarizes the biochemical aspects of DR and the main approaches for treating it.

In this paper a tuning procedure is proposed for event based PI controllers with Regular Quantization with Hysteresis (RQH) sampling law. The RQH is a generalization of Symmetric Send on Delta (SSOD) strategy which decreases the robustness requirements to avoid limit cycle oscillations and reduce the number of events needed for control, improving the overall performance of PI controllers in networked control systems. The tuning procedure takes into account not only classical robustness margins but also takes advantage of some specific robustness measures to avoid limit cycle oscillations induced by the sampler. As the robustness analysis depends on the Describing Function (DF) method, a study evaluating the effect of high order harmonics is provided, showing the validity of the tuning procedure. Some examples are included in which the usefulness of the tuning procedure is shown. [ABSTRACT FROM AUTHOR]

El objetivo del estudio es reflejar la realidad sobre los descansos obligatorios (libranza de guardias) de los médicos residentes en la provincia de Valencia.

Using different calorimetric techniques, the thermophysical and thermochemical properties of 2-, 3-, and 4-nitrobenzaldehyde were determined, including combustion energies, sublimation enthalpies, heat capacities, vaporization enthalpies, and enthalpies of formation in the gas phase. The latter were also calculated by means of the Gaussian G4 composite method and atomization reactions. Equations of heat capacity as functions of temperature, in the condensed phase, were measured experimentally, whereas the equations for heat capacities in the gas phase were calculated via computational techniques. By means of an isoperibolic combustion calorimeter, combustion energies were also determined. Sublimation enthalpies were obtained through thermogravimetry, by measuring the rate of mass loss as a function of temperature and applying the Langmuir equation. Fusion temperatures, fusion enthalpies, and heat capacities were determined using differential scanning calorimetry. The energetic influence of the nitro group on the aromatic ring is discussed briefly, and the presence of hydrogen bonding in 2-nitrobenzaldehyde is theoretically supported.

El comportamiento de la infección por SARS-CoV-2 obligó a la Organización Mundial de la Salud a emitir una convocatoria global de activación de mecanismos de emergencia para atender la crisis de salud pública latente. Las unidades de cuidados intensivos son uno de los principales recursos de los sistemas sanitarios dada la tasa de neumonías complicadas que presentan los pacientes infectados. En respuesta a los distintos lineamientos y diferentes niveles de evidencia de la información disponible, la Asociación Colombiana de Medicina Crítica y Cuidados Intensivos (AMCI) convocó un equipo multidisciplinario de expertos en medicina crítica para establecer una declaratoria de consenso de buena práctica clínica para la atención de pacientes con COVID-19.

La práctica rutinaria de la atención perioperatoria de los pacientes de cirugía cardiaca sigue sin estandarizarse y es muy variable debido a las interpretaciones diferenciales de la evidencia. Este estudio de consenso tiene como objetivo minimizar la variabilidad clínica estableciendo argumentos racionales, calificados, a través de la discusión y la evaluación de la evidencia.

A procedure for tuning PID controllers with SSOD sampling for FOPTD systems is proposed. It is based on the definition of a new robustness measure to avoid limit cycle oscillations, called the Tsypkin margin (M T). This margin is based on the Tsypkin method and does not rely on the attenuation of high order harmonics, as the describing function approaches require. Therefore, the avoidance of limit cycle oscillations can be guaranteed for any system, as a difference with the describing function based procedures. The procedure allows to obtain the PID controller that minimizes the disturbance IAE while fulfilling constraints on robustness to oscillations and on control action bumps due to the SSOD sampling. A freely available Java tool has been developed in order to simplify the application of the tuning procedure. In case of a non FOPTD system, it first calculates an approximate FOPTD model. The paper shows that the derivative filter parameter, N is a critical tuning parameter in order to find a compromise between performance and control action bumps. [ABSTRACT FROM AUTHOR]

In this paper we present a study about the robustness of event-based discrete PI controllers. Our approach is based on Sampled Describing Function technique, which has been used to characterize the non-linear effect of the Symmetric Send on Delta (SSOD) sampling strategy on the control loop. Through several examples this technique is proven to produce accurate results in predicting limit cycle oscillations and to provide guidelines to avoid them, either by detuning the controller or increasing the sampling period.

Ayahuasca (caapi, yajé), is a psychoactive brew from the Amazon Basin region of South America traditionally considered a “master plant.” It is prepared as a decoction from Banisteriopsis caapiand Psychotria viridis, which it is thought that it stimulates creative thinking and visual creativity. Native healers of the Orinoco and Amazon basins have used traditionally ayahuasca as a healing tool for multiple purposes, particularly to treat psychological disorders in the patients, with some beneficial effects experimentally and clinically validated. Recently, several syncretic religions, as the “União de Vegetal” (UDV) group in Brazil, have been spread around the world. The use of ayahuasca has been popularized by internet and smart-shops, bringing the psychoactive substance to new highs, emerging new “ayahuasqueros.” Ayahuasca has alkaloids as β-carbolines and dimethyltryptamines, which inhibit the monoamine oxidase and active the 5-HT2A(5-hydroxytryptamine) receptor, respectively, resulting in hallucinations in the users. Ayahuasca induces a psychedelic change in the anteroposterior coupling of the electrophysiological brain oscillations in humans. Traditional ayahuasca beverage is generating pharmacological, commercial and spiritual interest among the scientific community, government people, and different populations worldwide. The goal of this article is to report about the uses, chemistry and biological activities of ayahuasca.

In this work, we determine, both experimentally and computationally, structural and thermochemical properties of the methyl 2- and 4-methoxybenzoates. Combustion and vaporization enthalpies of these compounds were obtained experimentally through combustion calorimetry and thermogravimetry. From these properties, their standard molar enthalpies of formation in the gas phase, at T= 298.15 K, were also determined. In addition, we computed gas-phase enthalpies of formation of methyl 2-, 3-, and 4-methoxybenzoates using the composite method Gaussian G4, atomization reactions, and a weighted Boltzmann average. This average was performed over the stable conformers of each compound, and the respective Gibbs energies were used to compute the weights for the Boltzmann average. The analyses of the electronic density of the molecules and of noncovalent interactions were performed as well. We found a good agreement between our experimental and computational enthalpies of formation of methyl 2- and 4-methoxybenzoates. Finally, we discuss the enthalpic effects, as a function of the relative position of the methoxy and methyl groups, upon the benzoate base structure.

Hibiscus sabdariffa is a medicinal plant consumed as a diuretic and anti-obesity remedy. Several pharmacological studies have shown its beneficial effects in metabolism. Peroxisome proliferator-activated receptors δ and γ may play a role in the actions of H. sabdariffa. These nuclear receptors regulate lipid and glucose metabolism and are therapeutic targets for type 2 diabetes. This research aimed to perform a phytochemical study guided by a bioassay from H. sabdariffa to identify compounds with peroxisome proliferator-activated receptor δ and peroxisome proliferator-activated receptor γ agonist activity, supported by messenger ribonucleic acid expression, molecular docking, lipid accumulation, and an antihyperglycemic effect. An oral glucose tolerance test in mice with the aqueous extract of H. sabdariffa and the dichloromethane extract of H. sabdariffa was performed. The dichloromethane extract of H. sabdariffa exhibited an antihyperglycemic effect. The dichloromethane extract of H. sabdariffa was fractioned, and four fractions were evaluated in 3T3-L1 adipocytes on peroxisome proliferator-activated receptor δ , peroxisome proliferator-activated receptor γ , fatty acid transporter protein, and glucose transporter type 4 messenger ribonucleic acid expression. Fraction F3 exhibited peroxisome proliferator-activated receptor δ / γ dual agonist activity, and a further fractionation yielded two subfractions, F3-1 and F3-2, which also increased peroxisome proliferator-activated receptor δ and peroxisome proliferator-activated receptor γ expression. Subfractions were analyzed by GC/MS. The main compounds identified in F3-1 were linoleic acid, oleic acid, and palmitic acid, while in F3-2, the main compounds identified were α -amyrin and lupeol. These molecules were subjected to molecular docking analysis. α -Amyrin and lupeol showed the highest affinity. Moreover, both produced an increase in peroxisome proliferator-activated receptor δ , peroxisome proliferator-activated receptor γ , fatty acid transporter protein, and glucose transporter type 4 expression. Additionally, α -amyrin and lupeol decreased lipid accumulation in 3T3-L1 adipocytes and blood glucose in mice. Until now, α -amyrin and lupeol have not been reported with activity on peroxisome proliferator-activated receptors. This study provides evidence that α -amyrin and lupeol possess antidiabetic effects through a peroxisome proliferator-activated receptor δ / γ dual agonist action. [ABSTRACT FROM AUTHOR]

This study focused on incorporating total carotenoids (TC) into Pink Lady apples using vacuum-impregnation with carrot juice at 20, 30, 40, and 50°Brix and then assessing the shelf life of the impregnated apples after freeze-drying. The highest TC (12.30 ± 0.48 mg β-carotene/100 g) and minimal shrinkage were achieved using 20°Brix juice (20CJ). The freeze-drying of vacuum-impregnated apples with 20CJ reduced the time to reach equilibrium conditions compared with fresh apples. The shelf life of the freeze-dried impregnated samples was determined using time-to-fail models (TTF) at different conditions of package permeability (P= 2.17 × 10–15and 1.04 × 10–6g/s × Pa × m), temperature (T= 15, 25, and 35 °C), and relative humidity (RH = 0, 35, and 75%). TTF predictions indicate a T-independent shelf life, exceeding 105 days for P evaluated at RH < 35%. Sensory evaluation indicates that consumers preferred impregnated freeze-dried apples with intermediate hardness textures (above 18.14 N) and TC > 0.81 mg β-carotene/100 g in dried apples stored at RH = 35% and T= 15 °C.

The intramolecular hydrogen bond of the N–H···S type has been investigated sparingly by thermochemical and computational methods. In order to study this interaction, the standard molar enthalpies of formation in gaseous phase of diphenyl disulfide, 2,2′-diaminodiphenyl disulfide and 4,4′-diaminodiphenyl disulfide at T= 298.15 K were determined by experimental thermochemical methods and computational calculations. The experimental enthalpies of formation in gas-phase were obtained from enthalpies of formation in crystalline phase and enthalpies of sublimation. Enthalpies of formation in crystalline phase were obtained using rotatory bomb combustion calorimetry. By thermogravimetry, enthalpies of vaporization were obtained, and by combining them with enthalpies of fusion, the enthalpies of sublimation were calculated. The Gaussian-4 procedure and the atomization method were applied to obtain enthalpies of formation in gas-phase of the compounds under study. Theoretical and experimental values are in good agreement. Through natural bond orbital (NBO) analysis and a topological analysis of the electronic density, the intramolecular hydrogen bridge (N–H···S) in the 2,2′-diaminodiphenyl disulfide was confirmed. Finally, an enthalpic difference of 11.8 kJ·mol–1between the 2,2′-diaminodiphenyl disulfide and 4,4′-diaminodiphenyl disulfide was found, which is attributed to the intramolecular N–H···S interaction.

The TEMPO oxoammonium cation has been proven to be both an efficient oxidizing reagent and an electrophilic substrate frequently found in organic reactions. Here, we report that this versatile chemical reagent can also be used as an efficient promoter for C- and N-glycosylation reactions through a Ferrier rearrangement with moderate to high yields. This unprecedented reactivity is explained in terms of a Lewis acid activation of glycal by TEMPO+forming a type of glycal–TEMPO+mesomeric structure, which occurs through an extended vinylogous hyperconjugation toward the π*(O═N+)orbital [LP(O1)→ π*(C1═C2), π*(C1═C2)→ σ*(C3–O3), and LP(O6)→ π*(O═N+)]. This enables the formation of the respective Ferrier glycosyl cation, which is trapped by various nucleophiles. The extended hyperconjugation (or double hyperconjugation) toward the π*(O═N+)orbital, which confers the Lewis acid character of the TEMPO cation, was supported by natural bond orbital analysis at the M06-2X/6-311+G** level of theory.

The stereocontrolled synthesis of naturally occurring products containing a 5,5-spiroketal molecular structure represents a major synthetic problem. Moreover, in a previous work, the stereocontrolled synthesis of cephalosporolide E (ceph E), which presumably was obtained from its epimer congener (ceph F) through an acid-mediated equilibration process, was reported. Consequently, we performed a theoretical investigation to provide relevant information regarding the title question, and it was found that the higher thermodynamic stability of ceph E, relative to ceph F, is caused by an n → π* interaction between a lone electron pair of the oxygen atom of the spiroketal ring (nO) and the antibonding orbital of the carbonyl group (π*C=O). Although similar stereoelectronic interactions have been disclosed in other molecular structures, its presence in ceph E, and very likely in other related naturally occurring products, represents a novel nonanomeric stabilizing effect that should be introduced into the chemical literature.

El abordaje laparoscópico en la cirugía por complicaciones colorrectales es controvertido. Sin embargo, puede proporcionar ventajas sobre la cirugía abierta. El objetivo del estudio es comparar el abordaje laparoscópico vs. el abordaje abierto en la reintervención por complicaciones tras cirugía colorrectal.

In this paper we present a study of the appearance of limit cycles in event-based PID control systems. Our approach is based on the extension of the Tsypkin method, which has been widely used to study the relay control systems. A new margin has been obtained to measure the robustness to limit cycles of continuous controllers when applied on event based control loops. The margin has been calculated to characterize some well known PID controllers tuning methods applied to the control of FOPTD systems with SSOD sampling strategy.

Herein we present a theoretical study on the reaction of [Re(PPh2) (CO)3(phen)] (phen = 1,10-phenanthroline) and [Re(PPh2) (CO)3(bipy)] (bipy = 2,2′-bipyridine) toward methyl propiolate. In agreement with experimental results for the phen ligand, the coupling of the substituted acetylenic carbon with the nonsubstituted orthocarbon of the phen ligand is the preferred route from both kinetic and thermodynamic viewpoints with a Gibbs energy barrier of 18.8 kcal/mol and an exoergicity of 11.1 kcal/mol. There are other two routes, the insertion of the acetylenic fragment into the P–Re bond and the coupling between the substituted acetylenic carbon and a carbonyl ligand in cisdisposition, which are kinetically less favorable than the preferred route (by 2.8 and 1.9 kcal/mol, respectively). Compared with phen, the bipy ligand shows less electrophilic character and also less π electron delocalization due to the absence of the fused ring between the two pyridine rings. As a consequence, the route involving the coupling with a carbonyl ligand starts to be kinetically competitive, whereas the product of the attack to bipy is still the most stable and would be the one mainly obtained after spending enough time to reach thermal equilibrium.

In exploiting topological defects of liquid crystals as the targeting sites for trapping colloidal objects, previous work has relied on topographic features with uniform anchoring to create defects, achieving limited density and spacing of particles. We report a generalizable strategy to create topological defects on chemically patterned surfaces to assemble particles in precisely defined locations with a tunable interparticle distance at nanoscale dimensions. Informed by experimental observations and numerical simulations that indicate that liquid crystals, confined between a homeotropic-anchoring surface and a surface with lithographically defined planar-anchoring stripes in a homeotropic-anchoring background, display splay-bend deformation, we successfully create pairs of defects and subsequently trap particles with controlled spacing by designing patterns of intersecting stripes aligned at 45° with homeotropic-anchoring gaps at the intersections. Application of electric fields allows for dynamic control of trapped particles. The tunability, responsiveness, and adaptability of this platform provide the opportunities for assembly of colloidal structures toward functional materials.

Intramolecular C–C coupling between N-bonded 1,2-dimethylimidazole, 2-methyloxazoline, or 2-methylpyridine and either 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) ligands results from α-methyl group deprotonation in the coordination sphere of Re(CO)3fragments. The nucleophilic CH2group generated by the deprotonation attacks the 6 (bipy) or 2 (phen) positions of the diimines, dearomatizing the involved pyridine ring and generating new asymmetric, fac-capping tridentate ligands.

In this research work a control architecture which gives response to the requirements of new generation of flexible manufacturing systems in terms of flexibility, reconfigurability, robustness and autonomy is designed and implemented. To do so the main principles of the holonic manufacturing paradigm are applied using the IEC61499 function block (FB) technology. Unlike other similar research proposals, in this work FBs are not relegated to low-level control but are used to model manufacturing execution and control high-level control tasks. This is done with the objective of evaluating the viability of using FBs to develop holonic architectures in comparison to more established technologies like multi-agent systems. Moreover, the proposed control architecture also focuses on better integrating and exploiting the products' information to enhance its flexibility and adaptability. For this STEP-NC (ISO14649) is used to model richer process plans which include manufacturing alternatives and could be easily integrated in the control itself.

Thermochemical properties and intramolecular interactions of 2,2′-dinitrodiphenyl disulfide (2DNDPDS) and 4,4′-dinitrodiphenyl disulfide (4DNDPDS) were determined and analyzed. Their standard molar formation enthalpies in the gas phase (ΔfHm°(g)’s) were experimentally determined; theoretically, they were computed using the G4 composite method and atomization reactions. Specifically, ΔfHm°(g)’s were obtained by combining formation enthalpies in the condensed phase and enthalpies of phase change. Formation enthalpies in the condensed phase were determined experimentally through combustion energies, which in turn were found by means of a rotatory bomb combustion calorimeter. Sublimation enthalpies were derived from thermogravimetric experiments, measuring the rate of mass loss and using Langmuir and Clausius–Clapeyron equations. Fusion enthalpies and heat capacities of the solid and liquid phases were measured as functions of temperature by differential scanning calorimetry, and the heat capacities of the gas phase were calculated via molecular orbital calculations. Theoretical and experimental ΔfHm°(g)’s differed by <5.5kJ·mol–1, and isomerization enthalpies are discussed. In addition, using theoretical tools [natural bond orbitals (NBO) and quantum theory of atoms in molecules (QTAIM)], intramolecular interactions were analyzed. An uncommon hypervalent four-center six-electron interaction of type O···S–S···O was found in 2DNDPDS. This hypervalent interaction, in addition to the extent of conjugation between the aryl and NO2moieties and the formation of intramolecular C–H···S hydrogen bonds, counteracts the repulsion caused by steric repulsions. Hydrogen bonding was confirmed through geometric parameters as well as QTAIM.

Es importante estandarizar los procesos de ingreso a las UCI (UCI), y las prácticas establecidas por consenso determinan intervenciones de calidad que pueden potenciar contextos específicos. Las UCI son servicios finitos de alto costo que requieren políticas para garantizar el uso racional y poder brindar atención de calidad a los pacientes. En respuesta a la variabilidad de los criterios de ingreso a la UCI en el país, la Asociación Colombiana de Medicina Crítica y Cuidados Intensivos (AMCI) convocó un equipo multidisciplinario de expertos en medicina crítica para establecer un pronunciamiento científico mediante la metodología de consenso formal, principalmente por el método Delphi, acerca de las recomendaciones y prácticas que permitan homogenizar los criterios de ingreso a las UCI en Colombia. Como parte de la misión de la AMCI, se pretende impactar positivamente en los distintos niveles del sistema de salud (prestadores, administradores, aseguradores y gobierno) y que al final se refleje en beneficios para los pacientes críticos o en riesgo. El consenso invita a todas las UCI del país a seleccionar sus propios criterios teniendo en cuenta el listado de las recomendaciones que contiene; se aclara que los contenidos son generados en un contexto científico, académico y no comercial. Cada institución de salud debe ser garante, mediante la coordinación asistencial de las UCI, del uso responsable de estos criterios tanto para la atención segura y de calidad de los pacientes como de utilizarlos para las distintas relaciones comerciales que se establezcan con las administradoras de los regímenes de salud. Este documento tiene un alcance nacional y su contenido está previsto actualizarlo en un tiempo no mayor a 4años.

DensToolKit is a suite of cross-platform, optionally parallelized, programs for analyzing the molecular electron density ( ρ ) and several fields derived from it. Scalar and vector fields, such as the gradient of the electron density ( ∇ ρ ), electron localization function (ELF) and its gradient, localized orbital locator (LOL), region of slow electrons (RoSE), reduced density gradient, localized electrons detector (LED), information entropy, molecular electrostatic potential, kinetic energy densities K and G , among others, can be evaluated on zero, one, two, and three dimensional grids. The suite includes a program for searching critical points and bond paths of the electron density, under the framework of Quantum Theory of Atoms in Molecules. DensToolKit also evaluates the momentum space electron density on spatial grids, and the reduced density matrix of order one along lines joining two arbitrary atoms of a molecule. The source code is distributed under the GNU-GPLv3 license, and we release the code with the intent of establishing an open-source collaborative project. The style of DensToolKit’s code follows some of the guidelines of an object-oriented program. This allows us to supply the user with a simple manner for easily implement new scalar or vector fields, provided they are derived from any of the fields already implemented in the code. In this paper, we present some of the most salient features of the programs contained in the suite, some examples of how to run them, and the mathematical definitions of the implemented fields along with hints of how we optimized their evaluation. We benchmarked our suite against both a freely-available program and a commercial package. Speed-ups of ∼2×, and up to 12× were obtained using a non-parallel compilation of DensToolKit for the evaluation of fields. DensToolKit takes similar times for finding critical points, compared to a commercial package. Finally, we present some perspectives for the future development and growth of the suite. Program summary Program title: DensToolKit Catalogue identifier: AEXI_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEXI_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: GNU, General Public License, version 3 No. of lines in distributed program, including test data, etc.: 142037 No. of bytes in distributed program, including test data, etc.: 5517409 Distribution format: tar.gz Programming language: C++, bash. Computer: Any. Operating system: Linux, MacOSX, Windows (cygwin). RAM: The memory requirements grow quadratically with the number of primitives describing the wavefunction. A wavefunction with 1,500 primitives uses ∼17MB, and 2GB RAM are enough to process wavefunctions of around 10,000 primitives. A few more MB may be needed by some of the most demanding programs of the package if the number of primitives is large. Classification: 6.5, 7.3, 16, 16.1. External routines: (optional) gnuplot, povray, epstool, Graphics-Magick, epstopdf Nature of problem: The study of the electron density of molecules, some reactivity indices, and the topology of the electron density can be used to analyze the chemical nature, stability and reactivity of those molecules. Furthermore, the study of the electron density and functionals of it may help us in gaining a better understanding of the chemical bond. Reactivity indices and the molecular topological properties may also aid in molecular design. Solution method: The suite provides several programs in order to compute scalar and vector fields derivatives of the electron density. Those fields are obtained from a wavefunction file, which is in turn obtained from programs such as Nwchem, MolPro, etc. The functions, whereby the fields are computed, are implemented following mathematically standard but computationally optimized and parallelized algorithms built upon the Density Matrix. The suite provides several small but efficient programs, easily scriptable, for evaluation of the fields upon spatial grids. Regarding the topology analysis, the suite uses the algorithm proposed by Popelier, which uses the eigen-values of the Hessian of the electron density for locating the critical points. Bond paths are traced using a fifth-order Runge–Kutta–Dormand–Prince algorithm. Optional visualization of the produced data can be carried out by scripts generated by the suite, which can be parsed later to gnuplot, or povray. In addition, DensToolKit provides an open door for the user to program new scalar or vector fields, with almost complete functionality for evaluating such fields upon the same spatial grids as those implemented for the fields already provided in the suite. Restrictions: Wavefunctions with more than 99 nuclei must be input in wfx format. In the current version, wavefunctions that use pseudopotentials must have only one Additional Electron Density Function (EDF) entry in the wfx file, which in this case is the only accepted input format, and pseudopotential support is provided only in non-parallel compilation. Additional comments: A simple method for implementing new indices (derived from any of the implemented fields) is provided. In this manner, the final user may easily program his/her own scalar or vector field with a few code lines. Running time: Strongly dependent on the number of primitives used for approximating the wavefunction ( ∼ N 2 p ). It also depends on the evaluated number of points and type of field. Wavefunctions comprised of 1,500 primitives may take several hours to complete, while small molecules described by two or three hundred primitives take a few seconds. Typical running times are at least as fast as the times taken by some commercial or freely available codes. In many cases, the programs perform the computations with a speed-up of 2× (with respect to other available programs), and in some cases 10× speed-ups or more can be attained. [ABSTRACT FROM AUTHOR]

La obesidad es un problema de salud en México; la cirugía bariátrica es eficaz en el manejo de esta enfermedad; se requiere una endoscopia alta preoperatoria para detectar patología no diagnosticada; muchos obesos no presentan síntomas gastrointestinales y cuando los presentan suelen ser más intensos. Se ha evaluado poco la relación entre síntomas y hallazgos endoscópicos preoperatorios.

Rats must forage adaptively, choose safe foods, and avoid poisonous foods. The social transmission of food preference paradigm is useful to study learning and memory. Several studies have found that the associations formed in that paradigms are examples of declarative memory. Scopolamine induces interference in learning and consolidation of memories in diverse tasks. In this experiment, we evaluated the effect of one dose of the drug on the memory formed in several trials of this paradigm. In three groups, we evaluated the effect of administering saline and scopolamine with a control group that received no treatment. Results showed that the dose of scopolamine interfered with the consolidation of a series of trials in the transmission of preference. We discussed the effect in relation to different studies that used different tasks. The results support that scopolamine impaired consolidation on social transmission of food preference.

La acalasia es un trastorno motor primario del esófago, de etiología desconocida e incurable. La intención de todo tratamiento es debilitar el esfínter esofágico inferior. Los 3 tratamientos endoscópicos establecidos son: la aplicación de toxina botulínica y las dilataciones neumáticas, además de otro en desarrollo llamado POEM (per-oral endoscopic myotomy). Los 2 primeros logran de manera efectiva debilitar la presión del esfínter esofágico inferior, sin embargo su efectividad y duración son muy variables. En el caso de la toxina botulínica tiene una recurrencia de síntomas en un 50% de los pacientes a 6 meses y en un 100% al año, mientras que en las dilataciones neumáticas a 5 años solo el 60% de los pacientes permanecen asintomáticos y la necesidad de múltiples dilataciones es la regla en más del 90% de los pacientes. El factor predictivo para remisión duradera es una presión del esfínter esofágico inferior<15mmHg posterior a la realización de cualquier tipo de procedimiento. Una nueva técnica promisoria y en evolución es el POEM, con resultados iniciales similares a la miotomía de Heller, sin embargo aún nos encontramos a la espera de que la técnica madure y tenga mayor experiencia.

Primary cutaneous T-cell lymphomas (PCGD-TCLs) are considered a subgroup of aggressive cytotoxic T-cell lymphomas (CTCLs). We have taken advantage of a new, commercially available antibody that recognizes the T-cell receptor- (TCR-) subunit of the TCR in paraffin-embedded tissue. We have analyzed a series of 146 primary cutaneous T-cell lymphomas received for consultation or a second opinion in the CNIO Pathology Department. Cases were classified according to the World Health Organization 2008 classification as mycosis fungoides (MF; n=96), PCGD-TCLs (n=5), pagetoid reticulosis (n=6), CD30primary cutaneous anaplastic large cell lymphomas (n=5), primary cutaneous CD8aggressive epidermotropic CTCLs (n=3), primary cutaneous CTCL, not otherwise specified (n=4), and extranodal nasal-type NKT-cell lymphomas primarily affecting the skin or subcutaneous tissue (n=11). Sixteen cases of the newly named lymphomatoid papulosis type D (LyP-D; n=16) were also included. In those cases positive for TCR-, a further panel of 13 antibodies was used for analysis, including TIA-1, granzyme B, and perforin. Clinical and follow-up data were recorded in all cases. Twelve cases (8.2) were positive for TCR-, including 5 PCGD-TCLs, 2 MFs, and 5 LyP-Ds. All 5 PCGD-TCL patients and 1 MF patient died of the disease, whereas the other MF patient and all those with LyP-D were alive. All cases expressed cytotoxic markers, were frequently CD3CD8, and tended to lose CD5 and CD7 expressions. Eight of 12 and 5 of 11 cases were CD30and CD56, respectively. Interestingly, 512 TCR--positive cases also expressed TCR-BF1. All cases analyzed were negative for Epstein-Barr virus–encoded RNA. In conclusion, TCR- expression seems to be rare and is confined to cytotoxic primary cutaneous TCLs. Nevertheless, its expression is not exclusive to PCGD-TCLs, as TCR- protein can be found in other CTCLs. Moreover, its expression does not seem to be associated with bad prognosis by itself, as it can be found in cases with good and bad outcomes.

We have derived an explicit relation between the group delay velocity v_gd(ω), determined by the slope of the dispersion curves, and the nonlocal energy transport velocity v_E(ω) in a lossless, finite, one-dimensional photonic crystal. Using this relation, we find a simple link between v_gd(ω) and the group velocity vg(ω)(ω) defined in terms of the electromagnetic dwell time. It is shown that v_E(ω)≤v_gd(ω) for any frequency and v_E(ω)=v_gd(ω)=vg(ω)(ω) at the resonance frequencies of the transmission coefficient. It was established that the band structure of a finite periodic crystal is of great importance to describe and understand the properties of these velocities. In particular, it was shown that the occurrence of superluminal group delay velocities in these structures is closely related to the existence of null gaps in their dispersion relation. Calculations performed for a half-wave-quarter-wave stack show that the energy velocity remains always subluminal.

Both manganese and rhenium complexes of the type [M(bipy)(CO)3(N‐RIm)]+(bipy=2,2′‐bipyridine) undergo deprotonation of the central CH group of the N‐alkylimidazole (N‐RIm) ligand when treated with a strong base. However, the outcome of the reaction is very different for either metal. For Mn, the addition of the equimolar amount of an acid to the product of the deprotonation affords an N‐heterocyclic carbene (NHC) complex, whereas for Re, once the deprotonation of the central imidazole CH group has occurred, the bipy ligand undergoes a nucleophilic attack on an orthocarbon, affording the CC coupling product. The extension of these studies to pseudo‐octahedral [Mo(η3‐allyl)(bipy)(CO)2(N‐RIm)]+complexes has allowed us to isolate cationic NHC complexes (MnI‐type behavior), as well as their neutral imidazol‐2‐yl precursors. Theoretical studies of the reaction mechanisms using DFT computations were carried out on the deprotonation of [Mn(bipy)(CO)3(N‐PhIm)]+, [Re(bipy)(CO)3(N‐MesIm)]+, and [Mo(η3‐C4H7)(bipy)(CO)2(N‐MesIm)]+complexes (Mes=mesityl) at the B3LYP/6‐31G(d) (LANL2DZ for Mn, Re, and Mo) level of theory. Our results explain why different products have been found experimentally for Mn, Mo, and Re complexes. For Re, the process leading to a CC coupling product is clearly more favored than those forming an imidazol‐2‐yl product. In contrast, for Mn and Mo complexes, the lower stabilizing interaction between the central imidazole and orthobipy C atoms, along with the higher lability of the ligands, make the formation of an NHC‐type product kinetically more accessible, in good agreement with experimental findings.

The diabetic heart exhibits increased left ventricular (LV) mass and reduced ventricular function. However, this relationship has not been studied in patients with aortic stenosis (AS), a disease process that causes LV hypertrophy and dysfunction through a distinct mechanism of pressure overload. The aim of this study was to determine how diabetes mellitus (DM) affects LV remodeling and function in patients with severe AS.

An increasing number of patients are implanted with continuous-flow left ventricular assist devices (LVAD) for the treatment of severe congestive heart failure. In parallel with this growing experience has been an increase in knowledge of how these devices alter cardiac physiology and the important implications this has for cardiac function. Echocardiography offers the ability to provide serial noninvasive evaluation before and after LVAD implantation to document these changes, guide management decisions, and identify LVAD dysfunction. The authors detail a comprehensive assessment of LVAD function by transthoracic echocardiography.

No Abstract

Zwei Fliegen mit einer Klappe: Eine Abfolge aus Deprotonierung und Protonierung, bei der nur je ein Moläquivalent an Base und Säure zur Anwendung kommt, überführt zwei N‐Alkylimidazol‐Moleküle in einen N‐heterocyclischen Carben‐Liganden (siehe Schema; schwarz C, grau H, grün F, blau N, rot O, cyan Re, gelb S).

Complexes [Re(CO)3(N‐RIm)3]OTf (N‐RIm=N‐alkylimidazole, OTf=trifluoromethanesulfonate; 1 a–d) have been straightforwardly synthesised from [Re(OTf)(CO)5] and the appropriate N‐alkylimidazole. The reaction of compounds 1 a–dwith the strong base KN(SiMe3)2led to deprotonation of a central CH group of an imidazole ligand, thus affording very highly reactive derivatives. The latter can evolve through two different pathways, depending on the nature of the substituents of the imidazole ligands. Compound 1 acontains three N‐MeIm ligands, and its product 2 afeatures a C‐bound imidazol‐2‐yl ligand. When 2 ais treated with HOTf or MeOTf, rhenium N‐heterocyclic carbenes (NHCs) 3 aor 4 aare afforded as a result of the protonation or methylation, respectively, of the non‐coordinated N atom. The reaction of 2 awith [AuCl(PPh3)] led to the heterobimetallic compound 5, in which the N‐heterocyclic ligand is once again N‐bound to the Re atom and C‐coordinated to the gold fragment. For compounds 1 b–d, with at least one N‐arylimidazole ligand, deprotonation led to an unprecedented reactivity pattern: the carbanion generated by the deprotonation of the C2H group of an imidazole ligand attacks a central CH group of a neighbouring N‐RIm ligand, thus affording the product of CC coupling and ring‐opening of the imidazole moiety that has been attacked (2 c, d). The new complexes featured an amido‐type N atom that can be protonated or methylated, thus obtaining compounds 3 c, dor 4 c, d, respectively. The latter reaction forces a change in the disposition of the olefinic unit generated by the ring‐opening of the N‐RIm ligand from a cisoidto a transoidgeometry. Theoretical calculations help to rationalise the experimental observation of ring‐opening (when at least one of the substituents of the imidazole ligands is an aryl group) or tautomerisation of the N‐heterocyclic ligand to afford the imidazol‐2‐yl product.

This Microreview deals with the supramolecular chemistry of pyrazole metal complexes, in particular, complexes of pyrazoles with a nonsubstituted N–H group, which are able to engage in hydrogen bonding. The most pertinent general features of pyrazoles, in comparison with other heterocycles that are also popular ligands, and some aspects of the supramolecular chemistry of free pyrazoles are also included. In addition to the general supramolecular chemistry of pyrazole complexes, sections of this Microreview are devoted to liquid crystals, selfassembled species, and hosts for anions. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009

During a study of a colour-marked population of Lesser Spotted Woodpecker (LSW) in NE Spain we found two cases of cooperative breeding, in which two females and a male were rearing the brood. One of the females was involved in both cooperative breeding cases, in two consecutive years. We analysed the feeding contribution of each individual to nestling care as well as feeding rates to nestlings. In both cases the male showed a (compensatory) reduction in nestling feeding due to the involvement of the second female. Total feeding rate increased slightly compared to regular (noncooperative) monogamous pairs. The high breeding success found in the second case (six eggs/six nestlings) is thought to be due to the cooperation of the three adults in nestling care. The two cooperative breeding cases were found in territories that suffered from significant selective logging of dead trees. This logging is thought to be a possible anthropogenic example of the ecological constraints hypothesis and a significant factor that could force atypical cooperative breeding attempts. A locally biased sex-ratio might result in the cooperation of two females and a male in both cases. No evidence of kinship was found among members of the cooperative breeding teams. We could not determine whether the cooperative breeding cases were monogamous or polygamous.

The reactions of NaM(CO)3(bipy) (M Mn, Re) with ClCH2OCH3afford the (methoxy)methyl complexes M(CH2OCH3)(CO)3(bipy) (M Mn, 1; Re, 2), characterized by IR and NMR spectroscopy and, in the case of 1, also by X-ray diffraction. Highly electrophilic species, presumably cationic alkylideneoxonium complexes, although they were not detected, were prepared in situ by reaction of 1and 2with methyl triflate. These species react with neutral nucleophiles such as SMePh to generate the alkylidenesulfonium complexes M(CH2SPhMe)(CO)3(bipy)OTf-(M Mn, 3; Re, 4) and with styrene to give phenylcyclopropane and the corresponding triflate complexes M(OTf)(CO)3(bipy).

One of the most relevant topics in the biology of invasion concerns the genetic changes that occur subsequent to a species invasion, an issue of particular focus among conservation biologists. Colonizing a novel environment presents a genetic challenge to invading species because such species surely have not experienced the selective pressures presented by the environment. Here we ask, by what mechanisms and processes do alien species genetically naïve to their new environment, become successful invaders? We attempt to resolve this paradox by considering the interplay between an invader’s ability to modify its new environment, and genetic modifications imposed by the new environment. We postulate that epigenetic adaptations, and adaptive mutations are likely play a role in enhancing invasion success.One of the most relevant topics in the biology of invasion concerns the genetic changes that occur subsequent to a species invasion, an issue of particular focus among conservation biologists. Colonizing a novel environment presents a genetic challenge to invading species because such species surely have not experienced the selective pressures presented by the environment. Here we ask, by what mechanisms and processes do alien species genetically naïve to their new environment, become successful invaders? We attempt to resolve this paradox by considering the interplay between an invader’s ability to modify its new environment, and genetic modifications imposed by the new environment. We postulate that epigenetic adaptations, and adaptive mutations are likely play a role in enhancing invasion success.