Analysis of photorefractive optical damage in lithium niobate: application to planar waveguides.

Photorefractive optical damage of single beams in LiNbO(3) crystals is analyzed within a framework of two photoactive centres (Fe(2+)/Fe(3+) and Nb(Li) (4+)/Nb(Li) (5+)). It compares model simulations and significant experimental measurements in LiNbO(3) waveguides. A good agreement is found in the performed comparisons: photovoltaic currents, refractive index changes and, especially relevant, in degraded beam-profiles. The progress of the degraded wavefront has been simulated by implementing a finite-difference beam-propagating method which includes the model equations. These results, together with previous ones on grating recording, provide a comprehensive, satisfactory explanation of most important questions on photorefractive optical damage.

Dynamics of the dissolved organic matter in a stream-lake system within an extremely acid to neutral pH range: Agrio-Caviahue watershed.

The Agrio-Caviahue is a natural stream-lake system composed of the Upper Agrio River (UAR) -Lake Caviahue-Lower Agrio River (LAR). The system has a broad pH gradient from extremely acid in the hot spring to almost neutral pH only 60 km downstream the source, and varies as a function of the distance. The aim of this study was to analyze the dynamics of the dissolved organic matter (DOM) of this extreme system. For that matter, an absorbance and fluorescence-based characterization was performed on natural water samples and hydrophobic resin DOM extracts during different seasons in nine sampling stations. Between August and December, the hydrological connectivity is maximum due to precipitation and snowmelt, respectively. During these months, the stream that exits the lake governs the chemical characteristics downstream mainly in the period of high connectivity. In contrast, in the dry season when the flow of LAR is minimum, the two major affluents of this river influence its pH and DOM features, and deliver inputs of humified DOM from the wetlands where the tributaries are born. DOM was characterized by having low absorbance. The PARAFAC analysis of the fluorescent DOM (FDOM) validated three fluorescent components in the natural samples (with humic and non-humic features), two of which were also recorded in the extracts, meaning that no additional hydrophobic components were missed under the limit of detection of the fluorometer. The unique features of Agrio-Caviahue DOM resemble those found in DOM from Yellowstone hot springs, both acid and alkaline.

Malignant glaucoma after XEN45 implant. / Glaucoma maligno tras implante XEN45.

Minimally invasive glaucoma surgery for chronic open-angle glaucoma treatment tries to reduce the amount of chronic topical drug treatment, delaying invasive glaucoma surgery and diminishing the number of surgical complications. XEN45 uses subconjunctival drainage in order to reduce intraocular pressure. The report is presented of a patient following phacoemulsification, intraocular lens implantation and XEN45 implant. After four days acute malignant glaucoma was observed, with stage 3 athalamia requiring pars plana vitrectomy and secondary Ahmed valve implantation. The lower rate of complications due to minimally invasive glaucoma surgery has increased its use. Nevertheless, it is not free of severe adverse events, even requiring a multidisciplinary approach as in our malignant glaucoma report.

Understanding light intensity thresholds for catastrophic optical damage in LiNbO3.

The appearance of light intensity thresholds for catastrophic optical damage in LiNbO3 is satisfactorily explained by using a photorefractive model based on the Fe(2+)?Fe(3+) and NbLi(4+)?NbLi(5+) defect pairs. Model simulations of the photorefractive amplification gain as a function of the light intensity present sharp threshold behavior. A similar behavior is shown by the saturating refractive index change. In agreement with experiments, predicted thresholds appear shifted towards higher intensities (up to a 10(4) factor) when the Nb(Li) concentration is decreased or the temperature is increased. The model also explains very recent data on the threshold enhancement with the Fe(2+)/Fe(3+) ratio in optical waveguides.

On-line determination of fatty acid composition in intramuscular fat of Iberian pork loin by NIRs with a remote reflectance fibre optic probe.

A near infrared spectrometer equipped with a standard 210/210 bundle remote reflectance fibre-optic probe, with a 5×5 cm quartz window type, was used for the determination of fatty acids in the Longissimus dorsi muscle of Iberian breed swine. The fatty acids C14:0, C16:0, C16:1, C17:0, C17:1, C18:0, C18:1, C18:2, C18:3, Σpolyunsaturated, Σmonounsaturated and Σsaturated were determined in samples of intramuscular fat from Iberian breed swine by direct application of the fibre-optic probe onto the loin sample, with no treatment or manipulation of the sample. The regression method employed was modified partial least squares. The calibration results using the fibre-optic probe for 74 loin samples had multiple correlation coefficients (RSQ) for C14:0, C16:0, C16:1, C17:0, C17:1, C18:0, C18:1, C18:2, C18:3, Σpolyunsaturated, Σmonounsaturated and Σsaturated acid of 0.785, 0.798, 0.788, 0.825, 0.762, 0.765, 0.696, 0.859, 0.878, 0.807, 0.943, 0.858, respectively, and standard errors of prediction corrected for the same fatty acids (%) of 0.08, 0.63, 0.26, 0.02, 0.02, 0.51, 0,77, 0.64, 0.05, 1.06, 0.34, 0.70, respectively. The robustness of the method was checked by applying the fibre-optic probe to unknown samples of Iberian breed pork loin in a slaughterhouse, using 15 samples for the external validation.

Silicone granulomatous lymphadenopathy and siliconomas of the breast.

In the present study, two histologically-distinct cases of granulomatous lymphadenitis induced by dimethylpolysiloxane (silicone polymer) implants were studied. Four and six years after implant, and following surgery for breast cancer, painful homolateral axillary adenopathies were observed and biopsied. In both cases, histological examination led to a diagnosis of "silicone-induced granulomatous adenitis" requiring removal of implants. Foreign-body granulomas (siliconomas) were observed in surrounding tissue with no apparent rupture of implant capsules; however, visible retraction, hardening and scattered calcifications were noted. The presence of silica was revealed by incineration of a number of biopsied lymph nodes, a technique not hitherto used in the study of this pathology. A review is offered of the literature available.

Nonosseous athletic injuries of the elbow, forearm, and hand.

This article deals with soft-tissue injuries of the upper extremity incurred by competitive athletes. The authors describe the pathophysiology, conservative and operative management of musculotendinous elbow injuries, entrapment neuropathy, tendinous disorders, vascular injuries, and dermatologic conditions in athletes. Protective gear for many of the aforementioned injuries are also described.

Molecular monitoring of the treatment of patients with BCR/ABL (+) chronic myelogenous leukemia.

BACKGROUND: The molecular follow-up of patients with chronic myelogenous leukemia (CML) has been described as useful in other countries, but there are not data reported in Mexico. METHODS: All patients studied at Laboratories Clínicos de Puebla/Centro de Hematología y Medicina Interna de Puebla in which the BCR-ABL hybrid gene was identified by means of polymerase chain reaction were analyzed. In 22 individuals the molecular marker of the disease was studied at diagnosis and in different instances afterwards; these patients were treated with chemotherapy, interferon, autologous or allogeneic bone marrow transplantation. RESULTS: Only the six patients that were allografted from HLA-identical siblings cleared the molecular marker of the disease; the rest of them did not achieve molecular remissions. The median survival (SV) of the whole group has not been reached, whereas the 53-month SV is 68%. One of the allografted patients died as a result of complications of graft versus-host disease. CONCLUSIONS: We have found useful the molecular monitoring of the treatment of patients with CML. Using this approach, we found that molecular remissions can be accomplished only with allografting; however, other therapeutic approaches may also result in long-lasting hematologic remissions.

[Distal tibia peri-implant fracture with an intramedullary nail: a case report]. / Fractura peri-implante de tibia distal con clavo intramedular: presentación de un caso.

Peri-implant fractures of the distal tibia after intramedullary nailing are rare. We present a case of a fracture of the distal tibia at the site of the distal interlocking screw. We found two cases reported in the world literature. There are no cases reported in the Spanish literature.

A single high dose of chlorpyrifos reduces long-term basal c-fos expression in the rat arcuate hypothalamic nucleus / La administración de una dosis aguda de clorpirifós reduce a largo plazo la expresión basal de c-fos en el núcleo arqueado del hipotálamo

Chlorpyrifos (CPF) is an organophosphate compound used worldwide as a pesticide in agriculture that, after subcutaneous injection, keeps acetylcholinesterase (AChE) activity inhibited within an organism for months. Ample clinical and experimental evidence shows that CPF exposure induces relevant and persistent neurobehavioral deficits in humans and animals, even after one single episode/injection. Additionally, clinical and epidemiological studies evidence that a significant percentage (60%) of Gulf War veterans as well as agricultural workers suffering from acute OP intoxication may have developed intolerance to nicotine and ethanol-containing beverages. Consistent with it, administration of a single high dose of CPF to adult Wistar rats elicited long-lasting reduced voluntary ethanol drinking and increased sedation to ethanol without evidence of altered ethanol metabolism, which indicates that CPF-ethanol neurobiological interactions may exist. In this study, we explore whether CPF exposure induces significant disturbances in basal and/or ethanol-evoked neural activity in a set of cholinoceptive brain regions critically involved with neurobiological responses to ethanol. For this aim, brain regional c-fos expression in response to acute ethanol (1.5 or 3.0 g/kg, i.p.) or saline was assessed in adult male Wistar rats previously injected with either a single high dose of CPF (250 mg/kg, sc) or vehicle. We found that CPF administration reduces long-term basal, but not ethanol-evoked, c-fos expression in the arcuate hypothalamic nucleus. Because independent brain pathways may modulate acute responses to ethanol and voluntary ethanol consumption, we do not rule out the contribution of basal neural disturbances observed in the Arc to CPF-elicited ethanol avoidance.

El clorpirifós (CPF) es un compuesto organofosforado utilizado como plaguicida en todo el mundo. Después de ser inyectado de manera subcutánea, mantiene la actividad de la enzima acetilcolinesterasa (AChE) inhibida durante meses. Estudios clínicos y experimentales muestran que la exposición al CPF induce déficits neuroconductuales persistentes en seres humanos y animales, incluso después de un solo episodio/inyección. Además, estudios epidemiológicos evidencian que un porcentaje significativo (60%) de los veteranos de la Guerra del Golfo, así como los agricultores que sufren una intoxicación aguda por organofosforados, desarrollan intolerancia a la nicotina y las bebidas que contienen etanol. Datos experimentales mostraron que la administración de una sola dosis alta de CPF en ratas Wistar adultas provoca una reducción a largo plazo del consumo voluntario de etanol y un incremento en la sedación provocada por etanol sin evidencias de alteración del metabolismo de esta sustancia, lo que indica que pueden existir interacciones neurobiológicas entre CPF-etanol. En este estudio, se explora si la exposición a CPF induce alteraciones significativas en la actividad neuronal basal o evocada por el etanol en un conjunto de regiones colinoceptivas del cerebro involucradas en las respuestas neurobiológicas al etanol. Para ello, se evaluó la expresión de c-fos en respuesta a una dosis de etanol aguda (1.5 o 3.0 g/kg, ip) o solución salina en ratas Wistar macho adultas previamente inyectados con dosis aguda de CPF (250 mg/kg, sc) o un vehículo. Encontramos que la administración de CPF redujo la expresión basal de c-fos a largo plazo, pero no la evocada por el etanol en el núcleo arqueado del hipotalámo. Debido a que vías cerebrales independientes podrían modular las respuestas agudas al etanol y el consumo voluntario del mismo, no se descarta la contribución de las alteraciones neuronales basales observadas en el Arc en la evitación del consumo de etanol provocado por CPF.

Optical damage control via the Fe2+/Fe3+ ratio in proton-exchanged LiNbO3 waveguides.

Intensity thresholds for the onset of optical damage in alpha-phase proton-exchanged waveguides on undoped LiNbO(3) have been increased from the substrate value to a factor 500 greater. This has been achieved by increasing the exchange time, which in turn increases the [Fe(2+)]/[Fe(3+)] ratio in the guide. Intensity thresholds have been measured with a single-beam configuration, while [Fe(2+)]/[Fe(3+)] ratios have been determined from decay measurements during optical erasure of photorefractive gratings. In heavily Fe-doped guides, thresholds are too small to be measured, but the dependence of the Fe(2+) absorption on the exchange time appears similar to undoped samples.

Use of NIRS technology with a remote reflectance fibre-optic probe for predicting mineral composition (Ca, K, P, Fe, Mn, Na, Zn), protein and moisture in alfalfa.

In the present work we study the use of near-infrared spectroscopy (NIRS) technology together with a remote reflectance fibre-optic probe for the analysis of major (Ca, K, P) and minor (Fe, Mn, Na, Zn) elements, protein and moisture in alfalfa. The method allows immediate analysis of the alfalfa without prior sample treatment or destruction through direct application of the fibre-optic probe on ground samples in the case of the mineral composition and on-ground and compacted (baled) samples in the case of protein and humidity. The regression method employed was modified partial least-squares (MPLS). The calibration results obtained using samples of alfalfa allowed the determination of Ca, K, P, Fe, Mn, Na and Zn, with a standard error of prediction (SEP(C)) and a correlation coefficient (RSQ) expressed in mg/kg of alfalfa of 1.37x10(3) and 0.878 for Ca, 1.10x10(3) and 0.899 for K, 227 and 0.909 for P, 103 and 0.948 for Fe, 5.1 and 0.843 for Mn, 86.2 and 0.979 for Na, and of 1.9 and 0.853 for Zn, respectively. The SEP(C) and RSQ values (in %) for protein and moisture in ground samples were 0.548 and 0.871 and 0.150 and 0.981, respectively; while in the compacted samples they were 0.564 and 0.826 and 0.262 and 0.935, respectively. The prediction capacity of the model and the robustness of the method were checked in the external validation in alfalfa samples of unknown composition, and the results confirmed the suitability of the method.

Estimation of the global evolution of atmospheric pollution in Salamanca (Spain) during the 1993-2001 period according to one global index (ORAQI).

The aim of this study has been to use a global index to measure the air quality in the city, apart from individual assessment of the values of the concentrations of the different pollutants. We calculated the ORAQI with the data obtained at four air-pollution monitoring stations located in the city of Salamanca over the period between 1993 and 2001. For the calculations, SO2, PM10, NO2, CO and O3 were used as the most significant pollutants for the surroundings of the monitoring stations. The evolution of this index over 9 years is reported, and the repercussion of the most characteristic pollutants of each season of the year on the ORAQI along the whole period analysed is studied. The importance of the summer pollution in the characterisation of the least polluted surroundings was observed. At the most polluted sites, a decrease in the values corresponding to winter occurs, leading the ORAQI to take similar values along the whole year. In general, taking into account the surroundings of all the monitoring stations, the quality of the air to which the inhabitants of the city of Salamanca are exposed to can be said to be good.