ABSTRACT Postoperative complications after intestinal anastomosis remain the main concern in abdominal surgery in horses. The aim of this study was to describe an end-to-end jejunal anastomosis with a mesenteric flap covering technique and its macroscopic and postoperative histological characteristics. This technique is based on a reinforcement to the conventional surgery performed with a simple interrupted suture pattern to prevent postoperative complications. Five previously premedicated horses with xylazine 0.5 mg/kg, acepromazine 0.03 mg/kg and tramadol 2 mg/kg were induced to general anesthesia with diazepam 0.25 mg/kg and ketamine 2.2 mg/kg. General anesthesia was maintained with a minimum alveolar concentration of 1.4 ± 0.2% of isoflurane. A midline abdominal wall approach was made. A 10 cm jejunal segment was selected for resection and end-to-end anastomosis. A mesenteric flap large enough and proportional to the perimeter of the suture line was cut to cover the anastomotic area, fixing it to the intestinal serosa with a simple non-perforating discontinuous suture. Two animals underwent relaparotomy on the 7th and 30th postoperative days to describe the macroscopic and histopathological characteristics of the anastomotic area. In the macroscopic evaluation, no adhesions were observed and the mesenteric lined was well adhered to the anastomotic line, without contraction or displacement. Histopathological findings evidenced a healing process and adaptation of the mesenteric flap to loose connective tissue, which included fibrocytes, collagen, and slight edema. This technique turned out to be effective and could be useful in cases where equine intestinal resection anastomosis is necessary.

RESUMEN Las complicaciones posoperatorias tras la anastomosis intestinal siguen siendo la principal preocupación en la cirugía abdominal en equinos. El objetivo del presente estudio fue describir una anastomosis término-terminal yeyunal con técnica de recubrimiento de colgajo mesentérico y sus características macroscópicas e histológicas posoperatorias. Esta técnica se fundamenta en un refuerzo a la cirugía convencional realizada con patrón de sutura simple interrumpida para prevenir complicaciones posoperatorias. Cinco equinos previamente premedicados con xilacina 0.5 mg/kg, acepromacina 0.03 mg/kg y tramadol 2 mg/kg fueron inducidos a anestesia general con diazepam 0.25 mg/kg y ketamina 2.2 mg/kg. La anestesia general se mantuvo con una concentración alveolar mínima de 1.4 ± 0.2% de isofluorano. Se hizo un abordaje de la pared abdominal por línea media. Se seleccionó un segmento yeyunal de 10 cm para resección y anastomosis término-terminal. Se cortó un colgajo mesentérico lo suficiente- mente grande y proporcional al perímetro de la línea de sutura para recubrir el área anastomótica, fijándose a la serosa intestinal con sutura discontinua no perforante sim- ple. Dos animales fueron sometidos a relaparotomía en los días 7 y 30 posoperatorios para describir las características macroscópicas e histopatológicas del área anastomótica. En la evaluación macroscópica no se observaron adherencias y el recubrimiento mesentérico estaba bien adherido a la línea anastomótica, sin contracción ni desplaza- miento. Los hallazgos histopatológicos evidenciaron un proceso de curación y adaptación del colgajo mesentérico a un tejido conectivo laxo, que incluía fibrocitos, colágeno y un ligero edema. Esta técnica resultó ser eficaz y podría ser útil en los casos en que sea necesaria la anastomosis de resección intestinal equina.

Abstract: The use of a software application, designed to support medical specialists in the selection of the drug to be prescribed, is presented and evaluated. The “Medical Assistant” application evaluates the patient's data and through a decision tree, obtained from the administering of this data mining technique on the information of successful cases in the prescription of medicines, suggests the most appropriate medication according to the patient's data. In this initial version only the information of patients with Allergic Rhinitis was considered; Surveys were conducted to know the opinion of the specialists regarding the use of the application, which results revealed that specialists evaluated the use of the Medical Assistant in a range from regular to good.

Abstract Fricke dosimetry was performed in radiation fields of 60Co and 137Cs, corresponding to the Gammabeam 651PT irradiator loaded with new 60Co sources and a new Gammacell-3000 Elan self-irradiator with 137Cs. This last irradiator was purchased with funds from CONACYT. The gamma photons of 60Co from Gammabeam are using for sterilization of industrial products as well as in studies of physical and chemical properties changes of solid and aqueous solutions samples which are of the interest in research at the National Autonomous University of Mexico (UNAM). However, the difference in energy of the gamma photons from 60Co (1.17, 1.33 MeV) and 137Cs (0.66 MeV) makes interesting changes in research samples such as polymers, new dosimetric materials, organic compounds, etc., which are currently researching at the Nuclear Science Institute (ICN-UNAM). In order to use the radiation fields of irradiators, it is important to determine the exposure dose. In this paper, a successful methodology by using Fricke chemical dosimeter is reported. In this dosimeter is carried out the oxidation reaction in acid to ferric ion of ferrous. Dose rates distribution, less than 99 Gy/min, was determined in the Gammabeam irradiator. In the case of 137Cs irradiator, 10.89 Gy/min, at the center of the irradiation chamber was obtained. This value is in agreement to that certified measurement given by the Gammacell-3000 supplier. Because the sources are nonpoint, the uncertainties associated to the gamma doses were determinated. The two irradiators have adequate dose rates to continue supporting scientific research on different substances and materials, and offer the irradiation service at semi-industrial scale.

Resumen Se realizó la dosimetría en campos de radiación de 60Co y de 137Cs, correspondientes al irradiador Gammabeam 651PT, recargado con nuevas barras de 60Co y de un nuevo irradiador autoblindado Gammacell-3000 Elan de 137Cs que fue adquirido con fondos CONACYT. La radiación gamma de 60Co del Gammabeam, se utiliza para esterilización de productos industriales y para investigación en cambios de propiedades químicas y físicas de muestras sólidas y acuosas, de interés en la Universidad Nacional Autónoma de México (UNAM). Sin embargo, la diferencia de energía entre los fotones gamma del 60Co (1.17, 1.33 MeV) y del 137Cs (0.66 MeV) hace interesantes los cambios en las muestras de investigación, tales como polímeros, nuevos materiales dosimétricos, compuestos orgánicos, etc., que se investigan actualmente en el Instituto de Ciencias Nucleares de la UNAM. Para utilizar los campos de radiación de los irradiadores, es importante determinar las dosis de exposición. En este trabajo, se informa la metodología llevada a cabo para la dosimetría de las fuentes de radiación gamma usando el dosímetro químico de Fricke. En este, se lleva a cabo la reacción de oxidación en medio ácido del ion ferroso a férrico. Los resultados en el Gammabeam muestran distribuciones de razones de dosis menores a 99 Gy/min en su cámara de irradiación. En el caso del irradiador de 137Cs se obtuvo la razón de dosis, 10.89 Gy/min, al centro de su cámara; los resultados obtenidos con la dosimetría realizada en nuestro laboratorio coincidieron satisfactoriamente con los certificados otorgados previamente por el proveedor del Gammacell-3000. Dado que las fuentes no son puntuales en los irradiadores, se determinaron las incertidumbres asociadas a las dosis. Los dos irradiadores presentan razones de dosis adecuadas para continuar apoyando a la investigación científica y ofrecer también el servicio de irradiación a escala semi-industrial.

Abstract The applications that nanotechnology (NT) has on agriculture systems are diverse and promising because they have the potential to contribute in maintaining its productivity and efficiency by reducing costs and the quantity of synthetic agrochemicals employed. For instance, it is important to emphasize that by means of NT it is possible to develop encapsulated nanopesticides, stabilization of biopesticides and slow-release fertilizers. Nanoparticles of zinc oxide and silver are studied for their potential as antimicrobial, nanofertilizers and growth promoters of agricultural plants. Therefore, the aim of this study was to evaluate the effect of pure zinc oxide nanoparticles (ZnONPs) and ZnONPs with silver (ZnONPs + Ag) on growth of C. annuum plants. The sol-gel method was used to study the synthesis and characterization of NPs. Foliar application of ZnONPs to pepper plants was done manually once a week. The experimental design was completely at random with four treatments and five repetitions. Data collected were analyzed by ANOVA and Tukey's multiple range tests (p ≤ 0.05). Compared to control plants without the application of ZnONPs, treatments exposed to the application of ZnONPs + Ag (2.5%), were those that had a significant higher shoot and root growth, as well greater biomass production, with higher values of height (16.8%), leaf area (30.3%), total biomass production (59.5%), root dry biomass (112.5%), stem dry biomass (76%) and root length (24.4%). As compared to control plants, those treated with ZnONPs + Ag (2.5%) reported a quantitative increase of chlorophyll index (8%) and leave number (32.6%). The biological effect of the applied NPs, could be related to the zinc activity as a precursor in the production of auxins, which in turn could promote cell division and elongation, as well by its influence on the reactivity of indol acetic acid, which acts as hormonal phytoestimulant. Also ZnONPs might be involved in the biosynthesis of cytokinins and gibberellins; as well on the induction of greater activity of antioxidant enzymes.

Resumen Las aplicaciones de la nanotecnología (NT) en los sistemas agrícolas son diversas, ofreciendo el potencial para mejorar significativamente su productividad y eficiencia al reducir costos y cantidades de agroquímicos aplicados. Las nanopartículas (NPs) metálicas de óxido de zinc, cobre y fierro, ya sean puras o mezcladas con plata, están siendo estudiadas globalmente por su potencial agrícola como promotores de crecimiento, nanofertilizantes y antimicrobiales. Considerando lo antes señalado, el objetivo de este trabajo fue evaluar el efecto de NPs de óxido de zinc puras (NPsZnO) y con plata (NPsZnO+Ag) en el crecimiento de plantas de chile (Capsicum annuum). La síntesis y caracterización de las NPs mencionadas se realizó mediante el método de sol-gel. La aplicación foliar de las NPs a las plantas se hizo semanalmente; el diseño experimental empleado fue completamente al azar con cuatro tratamientos y cinco repeticiones. Los datos obtenidos se procesaron mediante un análisis de varianza y prueba de rango múltiple Tukey (p ≤ 0.05). Los resultados señalan que las plantas expuestas a la aplicación de NPsZnO + Ag al 2.5% en peso, tuvieron significativamente mayor crecimiento y producción de biomasa en comparación con las plantas del tratamiento control, mostrando valores superiores de altura (16.8%), área foliar (30.3%), producción de biomasa total (59.5%), biomasa seca de raíz (112.5%), biomasa seca de tallo (76%) y longitud de raíz (24.4%). También se observó un incremento del índice de clorofila (8%) y número de hojas (32.6%). El efecto promotor de crecimiento de las NPs aplicadas podría atribuirse a la actividad del zinc como precursor de la producción de auxinas que promueven división y elongación celular; así como por su influencia en la reactividad del ácido indolacético, el cual actúa como fitoestimulante hormonal. También puede ser factible que las NPs estudiadas estén involucradas en la biosíntesis de citoquininas y giberelinas; así como en la inducción de mayor actividad de enzimas antioxidantes.

We present 2D projections of 3D simulations of the quiet-sun radio-emission, at different frequencies on the centimeter-submillimeter wavelength range (specifically at 1.4, 3.9, 17, 34, 43, 110, 212 and 250 GHz). We have built a 3D, spherically symmetric, solar model and solved the classical equation of radiative transfer using quiet-sun temperature and electronic density models. We compare our results with Nobeyama Radio Heliograph observations at 17 GHz. The 3.9 and 43 GHz images will be useful to calibrate the observations of the new 5 meter millimeter telescope (RT5) which is going to be installed at "Sierra Negra" Volcano, in the state of Puebla, México, at an altitude of 4,600 m. over the sea level. This project is a collaboration between Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE) and Universidad Nacional Autónoma de México (UNAM).

Presentamos imágenes bidimensionales de simulaciones en 3D de la radioemisión solar en su régimen quieto a diferentes frecuencias, que van desde longitudes de onda centimétricas hasta submilimétricas (1.4, 3.9, 17, 34, 43, 110, 212 y 250 GHz). Construimos un modelo solar esférico 3D y resolvimos la ecuación clásica de transporte radiativo usando temperaturas y densidades electrónicas para el Sol Quieto. Comparamos nuestros resultados con observaciones del Nobeyama Radio Heliograph a 17 GHz. Las imágenes obtenidas a frecuencias de 3.9 GHz y 43 GHz serán de gran ayuda para calibrar las observaciones del nuevo telescopio milimétrico (RT5) que está siendo instalado en el Volcán "Sierra Negra", en el estado de Puebla, México, a una altitud de 4,600 m. Este proyecto es una colaboración entre el Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE) y la Universidad Nacional Autónoma de México (UNAM).

Phytoplankton growth in oligotrophic regions might be constrained by a low photosynthetic capacity related to nutrient stress. A reduced photosynthetic capacity has been documented by low values of the maximum quantum efficiency of charge separation (Fv/Fm) of photosystem II (PSII). In the present work, spatial and temporal variations of Fv/Fm in phytoplankton samples of the Eastern Tropical North Pacific (ETNP) off Mexico were characterized to explore the potential of this parameter as a nutrient stress indicator. Our results show that Fv/Fm was lower than 0.5 in most of the samples and that in surface waters this parameter was highly variable. The variability of Fv/Fm was related to the time of sampling, and Fv/Fm changes followed a day/night cycle with maximum values at dawn and a strong reduction at noon related to down-regulation of PSII activity. Enrichment experiments showed that Fv/Fm did not increase after nitrate addition to surface samples. These results suggest that photosynthesis of the phytoplankton community in the ETNP dominated by picoplankton, of which 60-80% was represented by prokaryote biomass (Prochloroccocus and other cyanobacteria), was not rate-limited under natural conditions. Therefore, low Fv/Fm values associated with PSII down-regulation and inherent of specific phytoplankton species are not indicative of nutrient stress in picoplankton-dominated environments such as the ETNP off Mexico. These sources of variability that are not directly associated with the nutritional status of the phytoplankton community should be taken into account when using Fv/Fm as a diagnostic tool for nutrient limitation.

El crecimiento del fitoplancton en zonas oligotróficas del océano puede estar restringido por una baja capacidad fotosintética asociada a una limitación por nutrientes. Se ha documentado la reducción de la capacidad fotosintética como valores bajos de la eficiencia cuántica máxima de separación de carga del fotosistema II (PSII, Fv /Fm). En el presente trabajo se caracterizó la variación espacial y temporal de Fv/Fm en muestras de fitoplancton de la región oceánica del Pacifico Nororiental Tropical (PNOT) ubicado frente a la costa de México para explorar el potencial de este parámetro como indicador de estrés nutricional. Los resultados mostraron que Fv /Fm fue menor de 0.5 en la mayoría de las muestras y presentó una alta variabilidad en muestras de agua recolectadas en la superficie. Esta variabilidad estuvo relacionada con la hora de muestreo. Los cambios de Fv /Fm siguieron un patrón día-noche con valores máximos al final de la tarde y una marcada disminución durante el mediodía asociada a la regulación en la actividad del PSII. En experimentos de enriquecimiento con diferentes nutrientes en muestras de agua superficial no se observó un aumento en Fv/Fm. La comunidad del PNOT estuvo dominada por picoplancton, del cual entre 60 y 80% estuvo constituido por biomasa procariota (Prochlorococcus y otras cianobacterias), y no se encontró evidencia de limitación de la tasa fotosintética por estrés nutricional en condiciones naturales. Por lo tanto, los valores bajos de Fv/Fm relacionados con la regulación de la actividad del PSII e inherentes a especies fitoplanctónicas específicas, no indican un estrés nutricional en ambientes dominados por el picoplancton, como es el caso del PNOT de México. La variabilidad que no está directamente asociada con el estado nutricional de la comunidad fitoplanctónica debe de tomarse en cuenta al usar Fv/Fm como herramienta diagnóstica de limitación por nutrientes.

Os microrganismos solubilizadores de fosfatos desempenham importante papel no suprimento de fósforo para as plantas. Isso tem motivado pesquisas em programas de inoculação controlada. O processo de seleção envolve várias etapas. Microrganismos isolados de cultivos de Pinus e Eucalyptus e selecionados em meio de cultura foram avaliados em 28 experimentos realizados em casa de vegetação com substrato ou solo de floresta ou de viveiro, esterilizados, sem ou com adubação fosfatada (fosfato monocálcico, fosfato de Araxá ou de Catalão). Em relação à produção de matéria seca, em um experimento, houve efeito positivo de três isolados (177, 251 e 310A); em outro, verificou-se efeito negativo de dois isolados (177 e 261). No teor de P no tecido foi verificado efeito positivo em sete tratamentos, envolvendo oito isolados (62, 177, 189, 198, 251, 262, 310A e 310B) e dois efeitos negativos (177 e 198). Quanto ao conteúdo de P na planta, foram verificados efeitos positivos em quatro experimentos, envolvendo os isolados 62, 189, 198, 251 e 310A. Os resultados obtidos na nutrição e no crescimento das plantas com a inoculação dos isolados 62, 189, 251 e 310A indicam a existência de potencial para ser utilizado em processos de seleção que visem à produção de inoculantes.

Phosphate solubilizing microorganisms play an important role in supplying phosphorous to plants. This ability has stimulated research on plant inoculation. In our study, microorganisms were isolated from Pinus and Eucalyptus plantations and selected in culture medium. They were then employed in a series of 28 experiments under greenhouse conditions in substrate, forest or sterilized nursery soil, with or without phosphate fertilization, in one of the following P forms: calcium phosphate, Araxá, or Catalão phosphate. Three isolates promoted a higher dry matter production (isolates 177, 251 and 310A) in one of the experiments. However, in another experiment the isolates 177 and 261 had a negative effect on this parameter. The inoculation of 8 isolates (62, 177, 198, 251, 262, 310A and 310B) in seven of the experiments increased the P concentration in plant tissues. In two experiments, the isolates 177 and 198 presented a negative effect. Phosphorous uptake was increased by the isolates 62, 189, 198, 251 and 310A, in four experiments. Results on P nutrition and growth obtained with the isolates 62, 189, 251 and 310A indicate that these isolates possess a potential well worth of being applied in further inoculation programs aiming at inoculum production.

Os sistemas agroflorestais podem aliar produção de alimentos com conservação dos recursos naturais, buscando economia de fertilizantes a partir da reciclagem de nutrientes. A produção de fitomassa e o aporte de nutrientes foram quantificados num cultivo em aléias e em área de vegetação nativa de cerrado em Botucatu (SP), com vistas em verificar as influências do sistema agroflorestal nos atributos químicos do solo. A leucena foi plantada em linhas em 1987, com espaçamento de 6 m, após calagem e aplicação de P. As linhas da leguminosa foram podadas anualmente, permitindo o cultivo intercalar de centeio + aveia e milho + feijão, durante a estação seca e chuvosa, respectivamente. A produção anual de fitomassa no sistema agroflorestal foi de 11.036 kg ha-1 de massa seca, com um aporte mineral pelas plantas de (kg ha-1) 149,0 de N, 9,4 de P, 70,0 de K, 75,2 de Ca e 31,1 de Mg. O pH do solo e os teores de Ca e Mg nesse sistema foram superiores aos do cerrado, o que se atribuiu ao efeito do calcário. A adubação verde, principalmente a fitomassa da leucena, colaborou na alteração dos teores de matéria orgânica, N e P no solo sob cultivo em aléias.

Agroforestry systems combine crop productivity with environmental sustainability while conserving fertilizer through nutrient cycling. Plant biomass production and nutrient inputs were measured in an alley cropping system and in native cerrado site at Botucatu, State of São Paulo, Brazil, and the influence of agroforestry practices on the soil chemical attributes were determined. Leucaena was planted in 1987, in hedgerows 6 m apart, following lime and P applications. Legume hedgerows were pruned annually, allowing for cereal intercropping of rye with oat and maize with beans during the dry and rainy season, respectively. Annual biomass production in the agroforestry system was 11,036 kg ha-1 (dry matter), and mineral inputs by plants, in kg ha-1, were 149.0-N, 9.4-P, 70.0-K, 75.2-Ca and 31.1-Mg. As a result, soil pH, Ca and Mg levels were higher than in the cerrado, which was attributed to a residual effect of liming. This kind of green manure, obtained mainly by leucaena biomass, contributed to increases in organic matter, as well as soil N and P levels, in the alley cropping system.