Emission characteristics of bulk aerosols excited by externally focused femtosecond filaments.

The bulk aerosol emissions excited by externally focused femtosecond laser filaments are characterized using time-resolved plasma imaging and spectroscopy. Images of N2 and N2+ plasma fluorescence are used to characterize the filament dimensions. Emission profiles from bulk Sr aerosols are studied, showing that several localized emission regions in the filament begin to develop for lower repetition rates and higher pulse energies. Plasma temperature and electron density profiles are determined using particle emissions along the length of short- and long-focused filaments, and results are compared for on-axis and side-collected spectra. The use of on-axis collection enables the sampling of light emitted over the entire length of the filament; however, the necessary back-propagation of light makes on-axis collection susceptible to self-absorption as the optical path is extended through the filament plasma column formed in bulk aerosols.

Phlebosclerotic colitis in a non-Asian patient: a case report.

BACKGROUND: Phlebosclerotic colitis is a rare condition with a high mortality. It has been seen almost exclusively in Asian patients who are ≥ 60 years old, with a slight male predominance. Although it predominantly affects the right colon and seems to be related in some cases to using natural herbal medicines, neither its etiology nor its pathogenesis are known. CASE PRESENTATION: We present an extremely rare case of a 62-year-old Spanish white man patient of non-Asian ethnicity with no history of using natural medications, who was diagnosed with phlebosclerotic colitis of submucosal veins. CONCLUSION: To date, this is the only case reported in Spain, and only the second reported for Europe, in the literature. Due to the nonspecific symptoms and insidious radiological findings of this disease (both in early and mild stages) as well as exclusive submucosal involvement presented here, it is necessary that the treating physician has a high level of suspicion for its diagnosis.

Transition from a uni- to a bimodal interfacial charge distribution in [Formula: see text]/[Formula: see text] upon cooling.

We present a combined resonant soft X-ray reflectivity and electric transport study of [Formula: see text]/[Formula: see text] field effect devices. The depth profiles with atomic layer resolution that are obtained from the resonant reflectivity reveal a pronounced temperature dependence of the two-dimensional electron liquid at the [Formula: see text]/[Formula: see text] interface. At room temperature the corresponding electrons are located close to the interface, extending down to 4 unit cells into the [Formula: see text] substrate. Upon cooling, however, these interface electrons assume a bimodal depth distribution: They spread out deeper into the [Formula: see text] and split into two distinct parts, namely one close to the interface with a thickness of about 4 unit cells and another centered around 9 unit cells from the interface. The results are consistent with theoretical predictions based on oxygen vacancies at the surface of the [Formula: see text] film and support the notion of a complex interplay between structural and electronic degrees of freedom.

KrCl and XeCl excilamps and LP-Hg lamp for UV and UV/H2O2 decolourization of dyes in water.

In the present study, the decolourization efficiencies of LP-Hg lamp, XeCl and KrCl excilamps at the same power density were compared for the decolourization of dyes in water by UV and UV/H2O2 processes in a batch reactor. Laboratory prototypes of XeCl and KrCl excilamps and a commercial LP-Hg lamp were studied as UV sources. Methylene Blue and Eliamine Blue dyes were used as model pollutants. The effect of the initial concentrations of dye and H2O2 in the TOC removal and kinetic parameters were also studied. The ratio of dye decolourization to the electric power consumption of the KrCl excilamp and LP-Hg lamp for the decolourization of Methylene Blue and Eliamine Blue were evaluated. As a result, the KrCl excilamp showed significantly higher decolourization efficiencies than LP-Hg lamp and XeCl excilamp, but the dye removal rate was significantly slower for Methylene Blue than for Eliamine Blue with this lamp. The KrCl lamp can be an alternative to conventional LP-Hg lamp for the decolourization of dyes by photodegradation, but it depends on the type of dye treated. The addition of H2O2 in a concentration between 0.05 and 0.09%v/v increases significantly the efficiency of the decolourization of Methylene Blue, and further increase does not lead to a higher increase in conversion. The experimental data were fitted to the one phase decay kinetic model with good agreement and the kinetic parameters were reported.

Site-selective spectroscopy with depth resolution using resonant x-ray reflectometry.

Combining dissimilar transition metal oxides (TMOs) into artificial heterostructures enables to create electronic interface systems with new electronic properties that do not exist in bulk. A detailed understanding of how such interfaces can be used to tailor physical properties requires characterization techniques capable to yield interface sensitive spectroscopic information with monolayer resolution. In this regard resonant x-ray reflectivity (RXR) provides a unique experimental tool to achieve exactly this. It yields the element specific electronic depth profiles in a non-destructive manner. Here, using a YBa2Cu3O7-δ (YBCO) thin film, we demonstrate that RXR is further capable to deliver site selectivity. By applying a new analysis scheme to RXR, which takes the atomic structure of the material into account, together with information of the local charge anisotropy of the resonant ions, we obtained spectroscopic information from the different Cu sites (e.g., chain and plane) throughout the film profile. While most of the film behaves bulk-like, we observe that the Cu-chains at the surface show characteristics of electron doping, whereas the Cu-planes closest to the surface exhibit an orbital reconstruction similar to that observed at La1-x Ca x MnO3/YBCO interfaces.

Dynamical Effects in Resonant X-Ray Diffraction.

Using resonant magnetic diffraction at the Ni L_{2,3} edge in a LaNiO_{3} superlattice, we show that dynamical effects beyond the standard kinematic approximation can drastically modify the resonant scattering cross section. In particular, the combination of extinction and refraction convert maxima to minima in the azimuthal-angle dependence of the diffracted intensity, which is commonly used to determine orbital and magnetic structures by resonant x-ray diffraction. We provide a comprehensive theoretical description of these effects by numerically solving Maxwell's equations in three dimensions. The understanding and description of dynamical diffraction enhances the capabilities of resonant x-ray scattering as a probe of electronic ordering phenomena in solids.

Numerical modelling of floating debris in the world's oceans.

A global ocean circulation model is coupled to a Lagrangian particle tracking model to simulate 30 years of input, transport and accumulation of floating debris in the world ocean. Using both terrestrial and maritime inputs, the modelling results clearly show the formation of five accumulation zones in the subtropical latitudes of the major ocean basins. The relative size and concentration of each clearly illustrate the dominance of the accumulation zones in the northern hemisphere, while smaller seas surrounded by densely populated areas are also shown to have a high concentration of floating debris. We also determine the relative contribution of different source regions to the total amount of material in a particular accumulation zone. This study provides a framework for describing the transport, distribution and accumulation of floating marine debris and can be continuously updated and adapted to assess scenarios reflecting changes in the production and disposal of plastic worldwide.

Magnetic frustration, phase competition, and the magnetoelectric effect in NdFe3(BO3)4.

We present an element selective resonant magnetic x-ray scattering study of NdFe3(BO3)4 as a function of temperature and applied magnetic field. Our measurements show that the magnetic order of the Nd sublattice is induced by the Fe spin order. When a magnetic field is applied parallel to the hexagonal basal plane, the helicoidal spin order is suppressed and a collinear ordering, where the moments are forced to align in a direction perpendicular to the applied magnetic field, is stabilized. This result excludes a noncollinear spin order as the origin of the magnetically induced electric polarization in this compound. Instead our data imply that magnetic frustration results in a phase competition, which is the origin of the magnetoelectric response.

The rabbit as an animal model for proctology research: anatomical and histological description.

PURPOSE: This study was designed to describe the surgical anatomy and histology of the rabbit anorectum comparing it to that of humans, in order to decide whether it can be a good experimental model for research in proctology. MATERIAL AND METHODS: This study of the anorectal region was performed on six female New Zealand white rabbits, weighting between 2.5-2.9 kg. An autopsy was performed immediately after sacrificing the animal and an anatomical and histological description was performed. RESULTS: The mean rectum and anal canal lengths were of 7.2 cm and 0.9 cm, respectively. The macroscopic study showed that the musculature of the anal canal is formed by the coccygeus muscle, which serves as puborectalis in humans. It also defined an external anal sphincter with a deep and superficial portion. The histological evaluation showed similarity to that of humans, with mucosa of simple columnar type, muscularis mucosae, a small submucosa, with a muscular wall divided into internal and external layers, separated by the myenteric plexus. CONCLUSION: The great similarity to both the anatomy and the histology of humans, appropriate size and easy-handling and care, make the rabbit an attractive animal for the use as experimental and research model in proctology.

The electronic phase diagram of the LaO(1-x)F(x)FeAs superconductor.

The competition of magnetic order and superconductivity is a key element in the physics of all unconventional superconductors, for example in high-transition-temperature cuprates, heavy fermions and organic superconductors. Here superconductivity is often found close to a quantum critical point where long-range antiferromagnetic order is gradually suppressed as a function of a control parameter, for example charge-carrier doping or pressure. It is believed that dynamic spin fluctuations associated with this quantum critical behaviour are crucial for the mechanism of superconductivity. Recently, high-temperature superconductivity has been discovered in iron pnictides, providing a new class of unconventional superconductors. Similar to other unconventional superconductors, the parent compounds of the pnictides show a magnetic ground state and superconductivity is induced on charge-carrier doping. In this Letter the structural and electronic phase diagram is investigated by means of X-ray scattering, muon spin relaxation and Mössbauer spectroscopy on the series LaO(1-x)F(x)FeAs. We find a discontinuous first-order-like change of the Néel temperature, the superconducting transition temperature and the respective order parameters. Our results strongly question the relevance of quantum critical behaviour in iron pnictides and prove a strong coupling of the structural orthorhombic distortion and the magnetic order both disappearing at the phase boundary to the superconducting state.

High-field pauli-limiting behavior and strongly enhanced upper critical magnetic fields near the transition temperature of an arsenic-deficient LaO0.9F0.1FeAs1-delta superconductor.

We report upper critical field Bc2(T) data for disordered (arsenic-deficient) LaO0.9F0.1FeAs1-delta in a wide temperature and magnetic field range up to 47 T. Because of the large linear slope of Bc2 approximately -5.4 to -6.6 T/K near Tc approximately 28.5 K, the T dependence of the in-plane Bc2(T) shows a flattening near 23 K above 30 T which points to Pauli-limited behavior with Bc2(0) approximately 63-68 T. Our results are discussed in terms of disorder effects within [corrected] unconventional superconducting pairings.

75As NMR studies of superconducting LaFeAsO0.9F0.1.

We have performed 75As nuclear magnetic resonance measurements on aligned powders of the new LaFeAsO0.9F0.1 superconductor. In the normal state, we find a strong temperature dependence of the spin shift and Korringa behavior of the spin lattice relaxation rate. In the superconducting state, we find evidence for line nodes in the superconducting gap and spin-singlet pairing. Our measurements reveal a strong anisotropy of the spin lattice relaxation rate, which suggests that superconducting vortices contribute to the relaxation rate when the field is parallel to the c axis but not for the perpendicular direction.

Commensurate spin density wave in LaFeAsO: a local probe study.

We present a detailed study on the magnetic order in the undoped mother compound LaFeAsO of the recently discovered Fe-based superconductor LaFeAsO1-xFx. In particular, we present local probe measurements of the magnetic properties of LaFeAsO by means of 57Fe Mössbauer spectroscopy and muon-spin relaxation in zero external field along with magnetization and resistivity studies. These experiments prove a commensurate static magnetic order with a strongly reduced ordered moment of 0.25(5)muB at the iron site below T(N)=138 K, well separated from a structural phase transition at T(S)=156 K. The temperature dependence of the sublattice magnetization is determined and compared to theory. Using a four-band spin density wave model both, the size of the order parameter and the quick saturation below T(N) are reproduced.

Hereditary internal anal sphincter myopathy: the first Caribbean family.

Hereditary proctalgia is an extremely rare condition characterized by endosonographic evidence of internal anal sphincter (IAS) thickening and specific ultrastructural changes seen at light and electron microscopy (EM). We report the case of a 54-year-old Caribbean woman with severe proctalgia and IAS thickening, treated with IAS myectomy. Transmission EM showed PAS-positive inclusions and granulofibrillary smooth muscle inclusion bodies. Anal endosonography of 5 family members from 3 generations showed IAS thickening in all cases with reported proctalgia. The condition represents an isolated IAS myopathy which is a probable polysaccharide storage disease variant. This condition may require specific surgical therapy with specimen preservation and ultrastructural examination for optimal characterization and treatment.

[Mesenteric lymphangiomatosis. Case report]. / Linfangiomatosis mesenterica. Presentacion de un caso.

OBJECTIVE: Lymphangiomas are lesions usually presenting during childhood and are located mainly in the head and neck region; less than 5% are intraabdominal. Lymphangiomatosis is the term used for multifocal or diffuse lymphangiomas. METHODS AND RESULTS: We report the case of a mesenteric lymphangiomatosis presenting as an acute abdomen in a 19-year-old man, review the literature and discuss the clinical management of these patients. CONCLUSIONS: Prognosis and treatment of these lesions depends of its site of origin and extension, being complete surgical excision the optimal treatment.

Linfagiomatosis mesentérica. Presentación de un caso / Mesenteric lymphangiomatosis. Case report

OBJETIVO: El término linfangiomatosis se utiliza para definir los linfangiomas con afectación multifocal o difusa. Los linfangiomas son lesiones que se suelen presentar en la infancia y su localización más frecuente es cabeza y cuello, representando los linfangiomas intrabdominales menos de un 5%. MÉTODOS Y RESULTADOS: Presentamos un caso de linfangiomatosis mesentérica en un paciente de 19 años de edad que se presenta como cuadro de abdomen agudo, realizando revisión de la literatura y discusión del manejo de estos pacientes. CONCLUSIONES: El pronóstico y tratamiento de estas lesiones va a depender de su localización y extensión; siendo el tratamiento de elección la exéresis quirúrgica completa

OBJECTIVE: Lymphangiomas are lesions usually presenting during childhood and are located mainly in the head and neck region; less than 5% are intraabdominal. Lymphangiomatosis is the term used for multifocal or diffuse lymphangiomas. METHODS AND RESULTS: We report the case of a mesenteric lymphangiomatosis presenting as an acute abdomen in a 19-year-old man, review the literature and discuss the clinical management of these patients. CONCLUSIONS: Prognosis and treatment of these lesions depends of its site of origin and extension, being complete surgical excision the optimal treatment

Thyrotropin-releasing hormone receptor expression in thyroid follicular cells: a new paracrine role of C-cells?

Thyrotropin-releasing hormone (TRH) synthesized in the hypothalamus has the capability of inducing the release of thyroid-stimulating hormone (TSH) from the anterior pituitary, which in turn stimulates the production of thyroid hormones in the thyroid gland. Immunoreactivity for TRH and TRH-like peptides has been found in some tissues outside the nervous system, including thyroid. It has been demonstrated that thyroid C-cells express authentic TRH, affecting thyroid hormone secretion by follicular cells. Therefore, C-cells could have a paracrine role in thyroid homeostasis. If this hypothesis is true, follicular cells should express TRH receptors (TRH-Rs) for the paracrine modulation carried out by C-cells. In order to elucidate whether or not C-cell TRH production could act over follicular cells modulating thyroid function, we studied TRH-Rs expression in PC C13 follicular cells from rat thyroid, by means of immunofluorescence technique and RT-PCR analysis. We also investigated the possibility that C-cells present TRH-Rs for the autocrine control of its own TRH production. Our results showed consistent expression for both receptors, TRH-R1 and TRH-R2, in 6-23 C-cells, and only for TRH-R2 in PC C13 follicular cells. Our data provide new evidence for a novel intrathyroidal regulatory pathway of thyroid hormone secretion via paracrine/autocrine TRH signaling.

Tipificación del papilomavirus como método de cribado de la patología cervical en mujeres con el virus de la inmunodeficiencia humana / Human papilloma virus typing as a screening method for cervical lesions in women with HIV infection

Objetivo: Estudio transversal que compara la técnica de tipificación del papilomavirus humano (VPH) con la citología, en el diagnóstico precoz de la neoplasia de cérvix en mujeres con el virus de la inmunodeficiencia humana (VIH), así como la relación entre el nivel de inmunosupresión y la infección por el VPH. Material y métodos: Se seleccionó a 67 pacientes VIH-positivas que cumplían los criterios de inclusión. Se realizaron 3 pruebas: citología, tipificación del VPH y colposcopia-biopsia. Se valoraron los factores de riesgo para la patología cervical dependiente del VPH, subtipo de VPH, tipo de lesión citológica y lesión biopsiada, cifra de CD4/mm3 y carga viral. Resultados: El 35,8 por ciento de la muestra fue positiva para el VPH, el subtipo más frecuente fue el VPH 18 (9 casos). Los factores de riesgo más fuertemente asociados a la infección por el VPH fueron los antecedentes de drogadicción, prostitución y uso infrecuente del preservativo. Hubo 22 biopsias positivas. El test de tipificación resultó más sensible que la citología (63,6 frente a 45,5 por ciento) pero menos específico. La cifra media de CD4/mm3 en pacientes VPH-positivas fue de 255,75 frente a 529,58 en VPH-negativas (p = 0,000). Conclusiones: La prueba de tipificación, asociada a la citología, aumenta la sensibilidad en el diagnóstico precoz de la neoplasia de cérvix en mujeres infectadas por el VIH. Las bajas cifras de CD4 se asociaron significativamente con presencia de lesión cervical e infección por el VPH (AU)