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Pituitary abscesses are infrequent entities, often forgotten and hence rarely included in the differential diagnosis of sellar lesions. However, given that they share the clinical manifestations of other more common pathologies in this region, the treatment of pituitary abscesses is usually performed correctly without demonstrating a relevant delay in therapeutic decisions when surgical options are considered as the alternative of choice. Two patients with intrasellar expansive processes and endocrinological alterations who were diagnosed intraoperatively as having pituitary abscesses are presented. In both cases, transsphenoidal surgery was performed; adjuvant antibiotic treatment was established for just one of them. Both patients are currently without symptoms due to mass-effect; one of the patients continues exhibiting residual endocrinological alteration and no signs of relapse in imaging studies.

CONTEXT: Different polymorphisms of the endothelial nitric oxide synthase gene (NOS3) have been related to diabetic kidney disease. OBJECTIVE: To evaluate the association between advanced diabetic chronic kidney disease (ACKD) and the rs1799983 and rs2070744 poymorphisms of NOS3 in a population from the Gran Canaria island. DESIGN: Cross-sectional case-control study. SUBJECTS AND METHODS: Polymorphisms were genotyped in 152 subjects with ACKD secondary to type 2 diabetes [estimated glomerular filtration rate (eGFR)

Belle II DEPFET, PXD, and SVD Collaborations: et al., The Belle II experiment comes with a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric ee collider with energies tuned to ϒ(4S) resonance s=10.588 GeV. The accelerator has successfully completed the first phase of commissioning in 2016 and the first electron–positron collisions in Belle II took place in April 2018. Belle II features a newly designed silicon vertex detector based on DEPFET pixel and double-sided strip layers. Currently, a subset of the vertex detector is installed (Phase 2 of the experiment). Installation of the full detector (Phase 3) will be completed by the end of 2018. This paper describes the Phase 2 arrangement of the Belle II silicon vertex detector, with focus on the interconnection of detectors and their integration with the software framework of Belle II. Alignment issues are discussed based on detector simulations and first acquired data., This work is supported by MSCA-RISE, European Union project JENNIFER (EU grant n. 644294), MEXT, Japan, WPI, and JSPS (Japan); ARC (Australia); BMWFW (Austria); MSMT, Czech Republic, GAUK 404316 (Czech Republic); AIDA-2020 (Germany); DAE, India and DST (India); INFN (Italy); NRF-2016K1A3A7A09005605 and RSRI (Korea); MNiSW (Poland); Federal Ministry of Education and Research (BMBF, Germany); and MINECO, Spain grant FPA2015-71292-C2-1-P (Spain).

The main aim of this work is to present a simple method, based on analytical expressions, for obtaining the temperature increase due to the Joule effect inside the metallic walls of an RF accelerating component. This technique relies on solving the 1-D heat-transfer equation for a thick wall, considering that the heat sources inside the wall are the ohmic losses produced by the RF electromagnetic fields penetrating the metal with finite electrical conductivity. Furthermore, it is discussed how the theoretical expressions of this method can be applied to obtain an approximation to the temperature increase in realistic 3-D RF accelerating structures, taking as an example the cavity of an RF electron photoinjector and a traveling wave linac cavity. These theoretical results have been benchmarked with numerical simulations carried out with commercial finite-element method (FEM) software, finding good agreement among them. Besides, the advantage of the analytical method with respect to the numerical simulations is evidenced. In particular, the model could be very useful during the design and optimization phase of RF accelerating structures, where many different combinations of parameters must be analyzed in order to obtain the proper working point of the device, allowing to save time and speed up the process. However, it must be mentioned that the method described in this article is intended to provide a quick approximation to the temperature increase in the device, which of course is not as accurate as the proper 3-D numerical simulations of the component. European Union’s Horizon 2020 Research and Innovation Programme under Grant 777431 (XLS CompactLight) Valencian Regional Government VALi+D Postdoctoral under Grant APOSTD/2019/155 The main aim of this work is to present a simple method, based on analytical expressions, for obtaining the temperature increase due to the Joule effect inside the metallic walls of an RF accelerating component. This technique relies on solving the 1-D heat-transfer equation for a thick wall, considering that the heat sources inside the wall are the ohmic losses produced by the RF electromagnetic fields penetrating the metal with finite electrical conductivity. Furthermore, it is discussed how the theoretical expressions of this method can be applied to obtain an approximation to the temperature increase in realistic 3-D RF accelerating structures, taking as an example the cavity of an RF electron photoinjector and a traveling wave linac cavity. These theoretical results have been benchmarked with numerical simulations carried out with commercial finite-element method (FEM) software, finding good agreement among them. Besides, the advantage of the analytical method with respect to the numerical simulations is evidenced. In particular, the model could be very useful during the design and optimization phase of RF accelerating structures, where many different combinations of parameters must be analyzed in order to obtain the proper working point of the device, allowing to save time and speed up the process. However, it must be mentioned that the method described in this article is intended to provide a quick approximation to the temperature increase in the device, which of course is not as accurate as the proper 3-D numerical simulations of the component.

Belle-II DEPFET and PXD Collaboration: et al., The Belle II experiment at the SuperKEKB energy-asymmetric e+ e- collider has completed a series of substantial upgrades and started collecting data in 2019. The experiment is expected to accumulate a data set of 50 ab−1 to explore new physics beyond the Standard Model at the intensity frontier. The pixel detector (PXD) of Belle II plays a key role in vertex determination. It has been developed using the DEpleted P-channel Field Effect Transistor (DEPFET) technology, which combines low power consumption in the active pixel area and low intrinsic noise with a very small material budget. In this paper, commissioning and performance of the PXD measured with first collision data are presented., This work is supported by MEXT, Japan, WPI, Japan, and JSPS (Japan); MSMT, GAUK 404316, MSCA-RISE project JENNIFER-2 (EU grant n. 822070) (Czech Republic); Federal Ministry of Education and Research (BMBF, Germany) and MINECO, Spain grant FPA2015-71292-C2-1-P (Spain).

RF photoinjectors have been under development for several decades to provide the high-brightness electron beams required for X-ray Free Electron Lasers. This paper proposes a photoinjector design that meets the Horizon 2020 CompactLight design study requirements. It consists of a 5.6-cell, X-band (12 GHz) RF gun, an emittance-compensating solenoid and two X-band traveling-wave structures that accelerate the beam out of the space-charge-dominated regime. The RF gun is intended to operate with a cathode gradient of 200 MV/m, and the TW structures at a gradient of 65 MV/m. The shape of the gun cavity cells was optimized to reduce the peak electric surface field. An assessment of the gun RF breakdown likelihood is presented as is a multipacting analysis for the gun coaxial coupler. RF pulse heating on the gun inner surfaces is also evaluated and beam dynamics simulations of the 100 MeV photoinjector are summarized.

[EN] Combining IR spectroscopy of NO adsorption on copper exchanged molecular sieves with the chabazite structure, i.e. Cu-SAPO-34 and Cu-SSZ-13, and theoretical calculations, different types of copper species have been identified. On one hand, [Cu¿OH]+ species can be accurately distinguished, characterized by a ¿NO frequency at 1788¿ 1798 cm¿1 depending on their location in the chabazite structure (6R vs. 8R) and composition (Cu-SAPO-34 vs. Cu-SSZ-13). On the other hand, dimeric copper oxo [Cu¿O¿ Cu]2+ species have been properly identified by means of DFT modelling, that proposes a ¿NO stretching frequency of 1887 cm¿1, which has been confirmed experimentally in the Cu-SAPO-34 sample. Finally the location of isolated Cu2+ ions either in the 6R units or in the 8R positions of the chabazite cavity could be accurately defined according to DFT data, and validated in the experimental IR spectra with IR bands between 1907 and 1950 cm¿1. Regarding to Cu+ species, IR spectroscopy of CO reveals different types of Cu+ species as evidenced by their ability to form mono, di and try carbonyls. The unambiguous differentiation of different types of copper species is of great interest in further identification of active sites for the NH3- SCR reaction., This work has been supported by the Spanish Government through "Severo Ochoa Program" (SEV 2012-0267), and MAT2015-71261-R, the European Union through ERC-AdG-2014-671093 (SynCatMatch); and the Generalitat Valenciana through the Prometeo program (PROMETEOII/2013/011). R.M. acknowledges "La Caixa - Severo Ochoa" International PhD Fellowships (call 2015).

Belle-II DEPFET and PXD Collaboration: et al., A DEpleted P-channel Field Effect Transistor (DEPFET) based pixel detector was developed for the Belle II VerteX Detector (VXD). It is designed to achieve a good impact parameter resolution better than 15𝜇m at the very high luminosity conditions of this experiment. In the first half of 2018 four final production modules have been deployed in the commissioning run of the detector and their performance is discussed., This work is supported by MEXT, WPI, and JSPS (Japan); MSMT, GAUK 404316, MSCA-RISE project JENNIFER (EU grant n. 644294) (Czech Republic); Federal Ministry of Education and Research (BMBF, Germany) and MINECO grant FPA2015-71292-C2-1-P (Spain).

In this letter, we evaluate potential of linear $e^+e^-$ colliders to measure the top quark mass in radiative events and in a suitable short-distance scheme. We present a calculation of the differential cross section for production of a top quark pair in association with an energetic photon from initial state radiation, as a function of the invariant mass of the $t\bar{t}$ system. This {\it matched} calculation includes the QCD enhancement of the cross section around the $t\bar{t}$ production threshold and remains valid in the continuum well above the threshold. The uncertainty in the top mass determination is evaluated in realistic operating scenarios for the Compact Linear Collider (CLIC) and the International Linear Collider (ILC), including the statistical uncertainty and the theoretical and experimental systematic uncertainties. With this method, the top quark mass can be determined with a precision of $110$ MeV in the initial stage of CLIC, with $1$ ab$^{-1}$ at $\sqrt{s} =$ 380 GeV, and with a precision of approximately $150$ MeV at the ILC, with $L = 4$ ab$^{-1}$ at $\sqrt{s}= 500$ GeV. Radiative events allow measurements of the top quark mass at different renormalization scales, and we demonstrate that such a measurement can yield a statistically significant test of the evolution of the MSR mass $m_t^{\rm MSR}(R)$ for scales $R< m_t$., 10 pages + bibliography

Resumen Introduccion Aunque los criterios para el diagnostico sindromico de la diabetes mellitus (DM) estan definidos, el protocolo de identificacion de su etiologia, clave para la planificacion del tratamiento, no esta tan establecido. Etiopatogenia La DM tipo 1 se debe a la destruccion inmunomediada de las celulas β pancreaticas, productoras de insulina. Como marcadores diagnosticos se utilizan los anticuerpos frente a antigenos del islote. La DM tipo 2, mucho mas frecuente, se debe a la insuficiente respuesta secretora de insulina frente a una demanda incrementada por la resistencia a la misma, generalmente asociada a sobrepeso. Existen tambien DM de etiologia especifica, como endocrinopatias, farmacos, enfermedades pancreaticas y mutaciones de genes concretos. Diagnostico La combinacion de la historia clinica y la determinacion de autoanticuerpos y el peptido C permitiran diagnosticar con una certeza razonable a la mayoria de los pacientes. En una minoria, seran los estudios geneticos los que confirmen el diagnostico.

The adsorption and dissociation of molecular O-2 over silver extended surfaces, nanoparticles and clusters of different size, as well as the reaction between adsorbed O-2 and H-2 to form less nucleophilic hydroperoxide groups have been investigated by means of periodic DFT calculations. Hydroperoxide formation from O-2 and H-2 is in all systems kinetically favoured over O-2 dissociation, which becomes energetically forbidden on small planar clusters. The nature and reactivity towards propene of all oxygen species present on silver, including adsorbed molecular O-2, atomic O, and hydroperoxide groups, have been theoretically explored. Formation of the oxametallacycle intermediate involved in propene epoxidation is energetically accessible on subnanometric three-dimensional silver nanoparticles, but competitive pathways leading to hydrogen abstraction and allyl formation always involve lower activation barriers. Theoretical findings have been experimentally confirmed by Raman spectroscopy of O-2 adsorption and catalytic testing of planar and three dimensional silver clusters., The authors thank the Spanish Science and Innovation Ministry (MAT2011-28009, Consolider Ingenio 2010-MULTICAT, CSD2009-00050 and Severo Ochoa) for financial support, and Red Espanola de Supercomputacion (RES) and Centre de Calcul de la Universitat de Val'ncia for computing facilities and technical assistance. A. P. thanks the Spanish Science and Innovation Ministry (Juan de la Cierva program) for her grant.

The Compact Linear Collider (CLIC) is an option for a future e+e- collider operating at centre-of-mass energies up to 3 TeV, providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: sqrt(s) = 350 GeV, 1.4 TeV and 3 TeV. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung (e+e- -> ZH) and WW-fusion (e+e- -> Hnunu), resulting in precise measurements of the production cross sections, the Higgs total decay width Gamma_H, and model-independent determinations of the Higgs couplings. Operation at sqrt(s) > 1 TeV provides high-statistics samples of Higgs bosons produced through WW-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes e+e- -> ttH and e+e- -> HHnunu allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit., 42 pages, 29 figures, accepted for publication in the European Physical Journal C

Objective To evaluate the diagnostic yield of 201Thallium SPECT in the detection of local and/or regional lymph node dissemination of pharyngo-laryngeal carcinoma. Material and methods 29 Patients who had been diagnosed with pharyngo-laryngeal carcinoma were studied (mean age: 60.9 years). These patients had been treated by surgery, chemotherapy and radiotherapy. At between 3 and 6 months after finishing the treatment, all of them underwent a planar and SPECT study at 1 h after the administration of 148 MBq of 201Thallium. Uptake was scored on four grades: from 0 (no uptake) to 3 (very intense uptake). The presence or non-presence of lymph nodes with uptake was also evaluated. All the results on the scintigraphy were correlated with long term clinical and radiological follow-up (mean: 2.5 years). The studies were classified as positive for recurrence when the uptake was 2–3 and/or with presence of lymph nodes with uptake. Results We obtained 9 true positive, 14 true negative, 3 false positive and 3 false negative results. Sensitivity was 75%, specificity was 82.4%, positive predictive value was 75% and negative predictive value was 82.4%. Two out of three false positives corresponded to the surgical bed uptake and one was attributed to the laterocervical lymph nodes. The three false negatives had grade 1 uptakes, two of them corresponding to pulmonary metastasis without evidence of local recurrence. Conclusions The use of 201Thallium SPECT in the prognostic evaluation in patients with a treated laryngeal carcinoma shows very acceptable results in the detection of local recurrence and/or regional lymph node dissemination.

Resumen Objetivo Evaluar el rendimiento del SPECT con 201 Talio en la deteccion de la recidiva local y/o diseminacion ganglionar regional del carcinoma faringolaringeo. Material y metodos Se estudiaron 29 pacientes con el diagnostico de carcinoma faringolaringeo (media: 60,9 anos), tratados con cirugia, quimioterapia y radioterapia. Entre 3 a 6 meses despues de finalizar el tratamiento, a todos se les practico un estudio planar y SPECT una hora despues de la administracion de 148 MBq de 201 Talio. La captacion se valoro en 4 grados (0 no captante-3 muy intenso) y se constato la presencia o no de ganglios captantes. El resultado gammagrafico se correlaciono con el seguimiento clinico y radiologico a largo plazo (media: 2,50 anos). Se valoraron como positivos de recurrencia, los estudios con captacion centrocervical focal de grado 2-3 o la presencia de adenopatias captantes. Resultados Se obtuvieron 9 verdaderos positivos, 14 verdaderos negativos, tres falsos positivos y tres falsos negativos. La sensibilidad fue del 75%, la especificidad del 82,4%, el valor predictivo positivo del 75% y el valor predictivo negativo del 82,4%. De los tres falsos positivos, dos correspondieron a captaciones en el lecho quirurgico y uno a captacion atribuida a ganglios laterocervicales. Los tres falsos negativos presentaron captaciones de grado 1, correspondiendo dos de ellos a metastasis pulmonares sin evidencia de recidiva local. Conclusion El uso del SPECT con 201 Talio en la evaluacion pronostica del paciente con carcinoma de laringe tratado muestra unos resultados muy aceptables para la deteccion de recidiva local y/o diseminacion ganglionar regional.

An S-band High-Gradient (HG) Radio Frequency (RF) laboratory is under construction and commissioning at IFIC. The purpose of the laboratory is to perform investigations of high-gradient phenomena and to develop normal-conducting RF technology, with special focus on RF systems for hadron-therapy. The layout of the facility is derived from the scheme of the Xbox-3 test facility at CERN [1] and uses medium peak-power (7.5 MW) and high repetition rate (400 Hz) klystrons, whose RF output is combined to drive two testing slots to the required power. The design and construction of the various components of the system started in 2016 and has been completed. The installation and commissioning of the laboratory is progressing, with first results expected before mid-2018. The technical characteristics of the different elements of the system and the commissioning status together with preliminary results are described.

The effect of Fe-doping on the oxygen vacancy energy formation and on the electronic structure of stoichiometric bulk and (001) surface of TiO2 anatase has been studied by means of periodic density functional calculations within the GGA+U approach. The vacancy energy formation is always lower for the surface than for the bulk. The presence of Fe causes only a minor perturbation of the atomic structure of anatase but strongly reduces the oxygen vacancy energy formation, especially at the surface. The present results provide additional and independent support to the claim that the enhanced catalytic activity of Au nanoparticles supported on Fe-doped TiO2 toward CO oxidation has its origin in the ease to create oxygen vacancies in the support.

New chiral CNN-pincer-type gold, palladium, and rhodium complexes containing N-heterocyclic carbene substituent and (S)-N-tert-butyl-methylpyrrolidine-2-carboxamide as chiral auxiliary have been synthesized and studied for asymmetric hydrogenation. The complexes were prepared by the silver carbene transfer route from the respective silver complex. The reaction with [RhCl(cod)]2 (cod = cycloocta-1,5-diene), PdCl2(CH3CN)2, or K[AuCl4] affords the corresponding cationic [Rh(cod)(ligand)]Cl, [PdCl(ligand)]Cl, and [AuCl(ligand)]Cl2 complexes in which the ligand functions effectively in a CNN coordination mode. The complexes catalyze the enantioselective hydrogenation of prochiral alkenes. Enantioselectivity is very sensitive to the NHC N-substituent, resulting in a useful switch in the predominant enantiomer.

Summary Objective Growth hormone (GH) replacement therapy is presently utilized in the treatment of adult GH deficiency (AGHD). Adult responses to GH treatment are highly variable and, apart from measurement of IGF-I, few tools are currently available for monitoring GH treatment progress. As GH receptors are expressed in certain blood cell types, changes in gene expression in peripheral blood can reflect perturbations induced as a result of GH therapy. Design/patients We have carried out a pilot study to identify GH-responsive genes in blood, and have assessed the utility of GH-responsive genes in monitoring GH therapy in AGHD. Blood was collected from ten women diagnosed with AGHD syndrome both before and 4 weeks after initiation of GH substitutive therapy. RNA was extracted from peripheral blood mononuclear cells (PBMCs) and changes in response to GH were detected using microarray-based gene analysis. Results All patients responded to GH replacement therapy, with serum levels of IGF-I increasing by an average of 307% (P = 0·0003) while IGFBP-3 increased by an average of 182% (P = 0·0002). Serum levels of triglycerides, LDL-C, HDL-C, APOA1 or APOB did not change after 1 month of GH treatment. By contrast, we detected an increase in Lp(a) serum levels (P = 0·0149). Using a stringent selection cutoff of P ≤ 0·05, paired analysis identified a set of transcripts that correlated with GH administration. We applied the multivariate statistical technique PLS-DA to the changes in gene expression, demonstrating their utility in differentiating untreated patients and those undergoing GH replacement therapy. Conclusion This study shows that GH-dependent effects on gene expression in PBMCs can be detected by microarray-based gene analysis, and our results establish a foundation for the further exploration of peripheral blood as a surrogate to detect exposure to GH therapy.

The interaction of the ethoxy radical with Cu(111), Ag(111), Pd(111) and Au(111) has been studied using a periodic density functional approach. The most stable adsorption site is the fcc with adsorption energies in the 1.1–2.2 eV interval. All analyses consistently indicate that ethoxy becomes negatively charged, that the presence of ethoxy slightly perturbs the electronic structure of the metallic surface, that the interaction is essentially of electrostatic character and not directional predicting a rather mobile species. The calculated adsorption energies are found to correlate almost linearly with the total net charge on the ethoxy moiety thus confirming that the electrostatic interactions dominate the bonding between this organic species and the underlying metallic surfaces.

A combination of XPS, IR spectroscopy of adsorbed CO, and DFT calculations has allowed us to identify different gold sites on Au/TiO2 catalysts, and to analyze the electronic and structural changes induced on the supported gold nanoparticles when adsorbing CO. The characteristics of low coordinated neutral Au0, slightly positively charged Auδ+, and cationic AuIII species have been studied, and the IR bands associated with CO adsorbed on these species have been determined. The shift in the νCO frequency not only depends on the charge on the particle or on the particular gold atom to which CO binds but also on the degree of coordination of gold atoms, that is, particle shape, and the capability of CO to modify this particle shape. It has been unequivocally shown by combining IR/DFT results and H/D isotopic exchange experiments that, among the different gold species identified, only the low coordinated neutral gold atoms not involved in Au−O−Ti linkages are responsible for H2 dissociation on Au/TiO2 catalysts.

The molecular structure of acrolein and crotonaldehyde adsorbed on clean and S-covered Cu(1 1 1) surfaces has been theoretically investigated in order to explain the mechanism of selective activation of the carbonyl group induced by the presence of small amounts of S on the metal surface. While on clean Cu(1 1 1) there is an equilibrium between a physisorbed and chemisorbed species, it is found that addition of small amounts of S enhances and modifies the metal–molecule interaction, in agreement with experimental evidence. On the S-covered Cu(1 1 1) the aldehyde is bonded to the surface through the O of the carbonyl group which is slightly stretched whereas the C C bond remains undistorted and far away from the surface. This geometrical conformation induced by the presence of coadsorbed S activates the C O group and renders the C C bond inaccessible to hydrogen adatoms. We argue that this is the origin of the chemoselectivity enhancement towards the crotyl alcohol experimentally observed.

The mechanism of olefin hydrogenation catalyzed by Pd II and Au III Schiff base complexes, both with an analog d 8 electronic structure, is analyzed by means of kinetic and computational methods. The computational study is able to explain the differences experimentally observed in relation to the influence of the solvent (polarity and proton donor ability) and of the hydrogen pressure on the Au III - and Pd II -catalyzed reaction mechanisms. These considerations can guide the proper selection of solid supports for heterogenization of catalysts to significantly increase their activity.

The mechanism of acid-catalyzed hydrocarbon reactions such as skeletal isomerization, hydride transfer, alkylation, dehydrogenation and cracking in superacid media and over solid zeolites is analyzed and compared. In particular, the stability, rearrangements and nature (reaction intermediates or transition states) of trivalent carbenium ions and non-classical pentacoordinated carbonium ions in homogeneous and heterogeneous phase are discussed. It is concluded that both carbenium and carbonium ions may exist as true reaction intermediates in zeolite-catalyzed processes only when the positive charge is not easily accessible to framework oxygen atoms.

Nanoparticles of gold on TiO2 are highly chemoselective for the reduction of substituted nitroaromatics, such as nitrostyrene. By combining kinetics and in situ IR spectroscopy, it has been found that there is a preferential adsorption of the reactant on the catalyst through the nitro group. IR studies of nitrobenzene, styrene, and nitrostyrene adsorption, together with quantum chemical calculations, show that the nitro and the olefinic groups adsorb weakly on the Au(111) and Au(001) surfaces, and that although a stronger adsorption occurs on low-coordinated atoms in gold nanoparticles, this adsorption is not selective. On the other hand, an energetically and geometrically favored adsorption through the nitro group occurs on the TiO2 support and in the interface between the gold nanoparticle and the TiO2 support. Such preferential adsorption is not observed with nanoparticles of gold on silica which, contrary to the Au/TiO2 catalyst, is not chemoselective for the reduction of substituted nitroaromatic compounds. Therefore, the high chemoselectiviy of the Au/TiO2 catalyst can be attributed to a cooperation between the gold nanoparticle and the support that preferentially activates the nitro group.

15N solid-state NMR and theoretical calculations were combined to investigate the Beckmann rearrangement of 15N-cyclohexanone oxime and 15N-cyclododecanone oxime over two MFI-type zeolites as catalysts, H-ZSM-5 and silicalite, containing Bronsted acid sites and silanol groups, respectively. The results demonstrated that the Beckmann rearrangement of cyclohexanone oxime to e-caprolactam occurs in the interior of the pores of MFI zeolites and that O-protonated e-caprolactam is formed over the Bronsted acid centers. The acid groups placed at the outer shell of the crystals, probably at the pore mouths, are also active; meanwhile, external silanol groups are significantly less active and less selective than the internal ones.

Objectives To report the case of a seven-year-old girl who had a bilateral papilledema with chronic cutaneous and articular manifestations. Chronic infantile neurological cutaneous and articular (CINCA) syndrome is a rare pediatric multisystem inflammatory condition. Optic disc abnormalities are the most common ocular manifestation of this syndrome and consist of optic-disc swelling, pseudopapilledema, and optic atrophy. Results: We report the case of a seven-year-old girl who had cutaneous manifestations from the age of three months, articular manifestations from the age of three years, and recurrent fever. Papilledema was the sign that led us to suspect the diagnosis of the CINCA syndrome, which was confirmed by our finding of the D303N de-novo mutation of the CIAS1 gene. The pathophysiology of papilledema remains unknown, but some reports suggest that the chronic meningoencephalitis associated with the CINCA syndrome may explain it. In our patient, the cause of papilledema was pseudotumor cerebri. She ...

This paper describes changes in the chromatic attributes (C* * *, H*, and S*) referring to the surface color of the red paprika pepper (Capsicum annuum L.) varieties, Americano and Fibola, grown in two substrates (sand and perlite) and under three fertilizer regimes (control and low levels of phosphorus and potassium). Three color attributes are related to the ripeness stages in the fruit and the best moment for their harvesting. Chroma (C*) and metric saturation (S*) increase rapidly between 60 and 70 days, particularly in Fii?½bola due to the great increase in the coordinate a*, reflecting the earlier ripening qualities of this variety compared with Americano. At the same time, the hue angle (H*) values decrease sharply in both varieties, with Fii?½bola once again leading the way and demonstrating its earlier ripening properties. In this way it can be calculated that Fii?½bola ripens at 65–70 days after fruit set and Americano at 70–75 days. The type of substrate has no significant effect, although at 6...

In this paper we explore the effect of $\delta$-ray emission, fluctuations in th e signal deposition on the detection of charged particles in silicon-based detec tors. We show that these two effects ultimately limit the resolution that can be achieved by interpolation of the signal in finely segmented position-sensitive solid-state devices., Comment: 5 pages

The protonation of ethene, propene, 1-butene, and iso-butene by acidic theta-1 zeolite to give covalent alkoxide intermediates has been theoretically investigated by means of cluster and periodic c...

The protonation of ethene by three different acid sites of theta-1 zeolite was theoretically studied to analyze the extent and relevance of the following aspects of heterogeneous catalysis: the local geometry of the Bronsted acid site in a particular zeolite, the size of the cluster used to model the catalyst, the degree of geometry relaxation around the active site, and the effects related to medium- and long-range interactions between the reaction site and its environment. It has been found that while the reaction energy is very sensitive to the local geometry of the site, the activation energy is mainly affected by the methodology used and by electrostatic effects on account of the carbocationic nature of the transition state.

The complete mechanism for the skeletal isomerization of but-1-ene catalyzed by theta-1 zeolite was investigated theoretically by means of DFT calculations, and the influence of the local geometry of the active site and of electrostatic effects on the geometries of the species involved and on activation and reaction energies were analyzed. It was found that whereas the geometry and stability of alkoxide intermediates are strongly influenced by the local geometry of the active site, the ionic transition states are mainly stabilized by electrostatic effects. Both aspects result in a lowering of the activation energies of the elementary steps that form the mechanism and therefore in enhanced reactivity compared with previous studies that used a general H3Si–OH–AlH2–O–SiH3 cluster.

La determinacion del cortisol plasmatico nocturno se ha propuesto como una alternativa en el diagnostico del sindrome de Cushing, principalmente para diferenciar entre pacientes con sindrome de Cushing y sujetos con estados de seudosindrome de Cushing. :Se analizaron retrospectivamente las medidas de cortisol plasmatico a medianoche en 28 pacientes con sospecha clinica de sindrome de Cushing y elevacion de la excrecion de cortisol libre urinario (20 pacientes con sindrome de Cushing y 8 con seudosindrome de Cushing). No se realizaron estudios endocrinologicos el dia del ingreso. En los 2 dias posteriores se tomaron muestras para cortisol serico a las 8.00 y a las 24.00 h. Los resultados se compararon con otras pruebas diagnosticas realizadas simultaneamente (cortisol libre urinario y test de supresion con 1 mg de dexametasona). El cortisol plasmatico a las 24.00 h fue el unico parametro que distinguio a todos los pacientes con sindrome de Cushing de aquellos con seudosindrome de Cushing. Su valor mas bajo entre los pacientes con sindrome de Cushing fue de 11,9 μg/dl, sin que se apreciaran diferencias entre los resultados obtenidos el segundo y el tercer dia de ingreso. En el grupo de pacientes con seudosindrome de Cushing, 3 casos presentaron un cortisol nocturno no suprimido durante el segundo dia de hospitalizacion (6,1–10,2 μg/dl), mientras que todas las determinaciones obtenidas 24 horas mas tarde proporcionaron valores menores de 5 μg/dl. Estos datos indican que el estudio del cortisol a medianoche puede requerir de un ingreso de al menos 48 h cuando se evalua a pacientes con seudosindrome de Cushing.

The mechanism of the bimolecular reactions of ethyl cation with ethane and propane and of s-propyl cation with ethane, propane, and isopentane is theoretically investigated by means of the B3PW91 density functional method. The study includes complete geometry optimization and characterization of the reactants, products, reaction intermediates, and transition states involved, calculation of the reaction enthalpies and activation energies for the different elemental steps, and obtainment of the equilibrium constants and relative reaction rate constants by means of transition state theory. It is found that the interaction of a carbenium ion with a saturated alkane always results in formation of a stable carbonium ion intermediate and that different intramolecular rearrangements of this common intermediate can explain the mechanism of acid-catalyzed hydrocarbon reactions, such as hydride transfer, disproportionation, dehydrogenation, and alkylation.

The ethane–ethene hydride transfer reaction on acid chabazite is used to test the performance of cluster calculations with respect to periodic ones for the study of bimolecular hydrocarbon reactions on acid zeolites. The following computational levels are considered: Hartree–Fock, MP2, aposteriori density functional theory (DFT) correlation using the PW91 functional, and several DFT hybrid B3PW91 procedures with different percentages of Hartree–Fock exchange. In all cases, a polarized basis set of double-zeta quality is used. Three periodic models with different numbers of acid sites and adsorbed substrates are explored to account for the effect of Si:Al ratio and coverage. Cluster and periodic calculations at different computational levels have been performed using the local geometries obtained from cluster constrained optimizations at the B3PW91 level. Our results indicate that the electrostatic field generated by the crystalline framework has only a relative influence on the stability of charged intermediates, that depends on the coverage and composition of the model, and also on the computational method used. It is noted in particular that the additional stability provided by the crystalline Madelung potential on the charged intermediate increases with the percentage of Hartree–Fock exchange in the DFT hybrid B3 scheme.

Density functional theory has been used to study the mechanism of the hydride transfer between alkanes and alkenes catalyzed by an acidic zeolite. The (C3H7−H−C3H7)+, (t-C4H9−H−t-C4H9)+, and (C3H7−H−t-C4H9)+ carbonium ion intermediates through which hydride transfer reactions proceed in the gas phase have been localized adsorbed on the catalyst surface, and they have been characterized, like in the gas phase, as reaction intermediates. However, they are about 25 kcal/mol less stable than separated reactants, and consequently, it will be difficult to detect them experimentally. The complete reaction path for the zeolite-catalyzed hydride transfer between propane and propene has been calculated, and it has been found that the (C3H7−H−C3H7)+ carbonium ion intermediate directly decomposes into propane and propene, and not into propane and a covalent alkoxide as previously reported. The activation barrier was calculated assuming this mechanism is in very good agreement with the only available estimation of thi...

Density functional theory is used to study the mechanism of double-bond isomerization and skeletal isomerization of linear butenes catalyzed by a protonated zeolite, which is simulated by a cluster consisting of two Si and one Al tetrahedra. The study includes complete geometry optimization and characterization of reactants, products, reaction intermediates and transition states, and calculation of the activation energies for the different processes involved. It is shown that the double bond isomerization proceeds by a concerted mechanism which does not involve the formation of either ionic or covalent alkoxy intermediates. According to this concerted mechanism, in one step the acid OH group of the zeolite protonates the double bond of adsorbed but-1-ene and the basic neighboring O atom of the cluster abstracts a hydrogen from the olefin, restoring the zeolite active site and yielding adsorbed but-2-ene. However, the mechanism of skeletal isomerization of linear butenes consists of three elementary steps:...

Juvenile rheumatoid arthritis (JRA) is the most commonly diagnosed rheumatic disease in children and may represent not a single disease, but rather a syndrome of diverse aetiologies in which inflammation is an exceedingly complex process. Oxidative free radical production at inflammation sites contributes to tissue damage and could also play a significant role in the pathogenesis of JRA. The aim of this study was to evaluate the antioxidant status and lipid peroxidation parameters related to the clinical form of JRA. Plasma malondialdehyde and hydroperoxide concentrations in children with polyarticular and systemic JRA subtypes were significantly higher than in controls. Plasma vitamin E and beta-carotene levels of the JRA children were lower in the three forms compared with healthy children. Patients with JRA present an imbalance in the oxidant-antioxidant system that manifests clearly in the polyarticular and systemic forms through an increase in lipoperoxidation products and significant decrease in the lipid-soluble antioxidants vitamin E and beta-carotene.

Several density functional theory based methods and the ab initio MP2 method were used to investigate the mechanism of secondary−secondary, tertiary−tertiary, and secondary−tertiary hydride-transfer reactions between alkanes and alkylcarbenium ions. All these reactions were found to proceed through a mechanism consisting of two steps: formation of a stable tight intermediate complex and decomposition of the complex to the products without activation energy. The optimized geometry of all the intermediate complexes is linear, with an open three-center two-electron C−H−C bond that is more or less symmetrical depending on the nature of the involved carbon atoms. By comparison of the results obtained at different levels of theory, it was shown that DFT-based methods provide optimized geometries in very good agreement with those obtained at the MP2 level, but the former fail in describing the energetics of the complex formation reactions studied. While DFT underestimates in some cases the stability of the inte...

The NH tautomerism of free base porphyrin is investigated at the semiempirical spin-unrestricted AM1 (UAM1) and ab initio RHF/3-21G levels. The UAM1 method provides delocalized geometries for all stationary structures without imposing any symmetry constraint. RHF/3-21G geometry optimizations have to be performed under symmetry restrictions to ensure that realistic delocalized structures are obtained. Both the semiempirical and the ab initio calculations predict that the interconversion between trans tautomers proceeds in an asynchronous two-step process via intermediate cis tautomers. The cis tautomers are characterized as minima in the potential energy surface and are 8–10 kcal mol−1 higher in energy. The activation energy for the trans → cis interconversion is calculated to be approximately 23 kcal mol−1 at the 3-21G level. The activation energy for the synchronous trans → trans interconversion is higher and has a value of 30.5 kcal mol−1. The activation energies obtained at the semiempirical UAM1 level are twice as large as the ab initio values.