El armamento entre los Mexicas

[ES] Estamos ante un trabajo que, en principio, se puede calificar de atrevido y laborioso. Es atrevido por lo que tiene de osado el intentar bucear en aguas no muy claras y en parajes poco conocidos; y es laborioso por la ardua tarea de encontrar e investigar las fuentes documentales (Códices prehispánicos y obras de los Cronistas, principalmente), etnográficas y arqueológicas existentes al respecto

El armamento entre los Mexicas

Marco Antonio Cervera Obregón. Madrid: CSIC, 2007. 208 páginas, 28x20 cm. I.S.B.N.: 978-84-00-08606-0

Estratificación del manto superior en Colombia usando función receptora de ondas

Utilizando formas de onda de sismos distantes registrados en estaciones sismológicas de banda ancha de 3 componentes, se analiza por medio de la función receptora de onda S (FRS) la conversión de la onda S a la onda P en las discontinuidades del manto superior y la corteza terrestre. Para incrementar la calidad de las señales, se agrupa la información por azimut y se utilizan técnicas de corrección por trayectoria y apilado de señales para cada estación. La migración a profundidad de las FRS muestra que la discontinuidad del límite litósfera-astenósfera (LAB) presenta anisotropía azimutal apreciable y relativa entre estaciones cercanas. Los valores de profundidades del LAB para el Caribe colombiano oscilan entre 70 y 90 km, mientras que para el Océano Pacífico se encuentran profundidades de hasta 140 km. En el continente las FRS muestran cambios apreciables entre estaciones localizadas en la costa pacífica cercanas a la zona de subducción con respecto a las ubicadas en las cordilleras. Los resultados obtenidos revelan una primera aproximación que explica la geometría del límite sísmico de la astenósfera y la litósfera, sin embargo es recomendable utilizar más y mejores registros para confirmar los valores de LAB aquí encontrados. La baja resolución espacial de las ondas S utilizadas para determinar la profundidad del LAB limitan los resultados encontrados a una incertidumbre del orden de las decenas de kilómetros.Abstract. Using waveforms from distant earthquakes recorded at 3 component broad band seismological stations, it is analyzed the S to P wave conversion at the upper most mantle and curst discontinuities with the receiver function of S wave (RFS) technique. To improve the data reliability, it is gathered by azimuth the information and the RFS are corrected by normal move out to be able to perform a stack per station. The RFS depth migration reveals that the lithosphere-asthenosphere boundary (LAB) discontinuity has an important azimuthal anisotropy and it is relative between near stations. The measure of the LAB depth for the Colombian Caribbean varies between 70 and 90 km, whilst for the Pacific Ocean is found depth even until 140 km. In the continent the RFS evidences important changes between stations close to the pacific coast close to subduction zone respect to those on the cordilleras. The results obtained reveal at first approximation, the geometry of the LAB, however incorporate more and better data is advice to confirm the LAB depth found. The S wave low spatial resolution used to determine the LAB depth limits the results found around dozen of kilometers uncertainty.Maestrí

El armamento entre los Mexicas

Marco Antonio Cervera Obregón. Madrid: CSIC, 2007. 208 páginas, 28x20 cm. I.S.B.N.: 978-84-00-08606-0

Metástasis en hueso maxilar superior de adenocarcinoma de esófago: presentación de un caso clínico

Las metástasis en cavidad oral son lesiones raras que representan aproximadamente el 1% de todas las neoplasias malignas de cavidad oral. Las metástasis orales se localizan en un 80-90% en mandíbula, siendo mas raras en maxilar superior. Las metástasis en tejidos blandos de boca son raras, y es encía donde con mayor frecuencia se localizan las metástasis en tejidos blandos en boca. Los tumores primarios que metastatizan a boca son los más frecuentes pulmón, mama y riñón. Las metástasis en cavidad oral es como consecuencia de una diseminación a distancia de la enfermedad e indica un mal pronóstico, con una supervivencia corta. Aquí presentamos un caso clínico de un paciente diagnosticado de adenocarcinoma de esófago que presentó metastasis en hueso maxilar superior izquierdo.Metastases in the oral cavity are rare lesions which represent approximately 1% of all malignant neoplasms in the oral cavity. Oral metastases are located in the mandible 80-90% on average, the maxilla location being rarer. Metastases in mouth soft tissue are also rare, and within these it is on the gums where they more frequently occur. Primary tumours which metastasize to mouth are most commonly: lung, breast and kidney. Oral cavity metastases appear as a result of distant disease spreading and show wrong prognosis, with short survival. Here we present a clinical case of a patient diagnosed with esophagus adenocarcinoma which presented metastasis in upper-left maxillary bone

Quantitative determination of the antitumor alkyl ether phospholipid edelfosine by reversed-phase liquid chromatography-electrospray mass spectrometry: application to cell uptake studies and characterization of drug delivery systems.

Edelfosine is a synthetic alkyl ether phospholipid that represents a promising class of antitumor agents. However, analytical methods to measure these type compounds are scarce. The lack of a reliable methodology to quantify edelfosine is a major problem in ongoing and scheduled preclinical and clinical trials with this drug. We evaluated the applicability of high-performance liquid chromatography–mass spectrometry to determine edelfosine in biological samples and polymeric delivery systems. Sample pre-treatment involved polymer precipitation or cell lysis with methanol. HPLC separation was performed on an Alltima RPC18 narrow-bore column and edelfosine quantification was done by electrospray ionization mass spectrometry (ESI-MS) using positive ion mode and selected ion monitoring. Assays were linear in the tested range of 0.3–10 μg/ml. The limit of quantification was 0.3 ng/sample in both matrices, namely biological samples and polymeric delivery systems. The interassay precision ranging from 0.79 to 1.49%, with relative errors of −6.7 and 12.8%. Mean extraction recovery was 95.6%. HPLC–ESI-MS is a reliable system for edelfosine analysis and quantification in samples from different sources, combining advantages of full automation (rapidity, ease of use, no need of extensive extraction procedures) with high analytical performance and throughput

In vitro and in vivo efficacy of edelfosine-loaded lipid nanoparticles against glioma.

Edelfosine is the prototype molecule of a family of anticancer drugs collectively known as synthetic alkyl-lysophospholipids. This drug holds promise as a selective antitumor agent, and a number of preclinical assays are in progress. In this study, we observe the accumulation of edelfosine in brain tissue after its oral administration in Compritol® and Precirol® lipid nanoparticles (LN). The high accumulation of edelfosine in brain was due to the inhibition of P-glycoprotein by Tween® 80, as verified using a P-glycoprotein drug interaction assay. Moreover, these LN were tested in vitro against the C6 glioma cell line, which was later employed to establish an in vivo xenograft mouse model of glioma. In vitro studies revealed that edelfosine-loaded LN induced an antiproliferative effect in C6 glioma cell line. In addition, in vivo oral administration of drug-loaded LN in NMRI nude mice bearing a C6 glioma xenograft tumor induced a highly significant reduction in tumor growth (p<0.01) fourteen days after the beginning of the treatment. Our results showed that Tween® 80 coated Compritol® and Precirol® LN can effectively inhibit the growth of C6 glioma cells in vitro and suggest that edelfosine-loaded LN represent an attractive option for the enhancement of antitumor activity on brain tumors in vivo

In situ modification of nanostructure configuration through the manipulation of hydrogen bonded amphiphile self-association

Herein, we report the synthesis of a novel amphiphilic salt containing a number of hydrogen bond donating (HBD) and accepting (HBA) functionalities. This amphiphile has been shown to self-associate via hydrogen bond formation in a DMSO solution, confirmed through a combination of NMR, UV-Vis and dynamic light scattering and supported by X-ray diffraction studies. The combination of different HBD and HBA functionalities within the amphiphile structure gives rise to a variety of competitive, self-associative hydrogen bonding modes that result in the formation of ‘frustrated’ hydrogen bonded nanostructures. These nanostructures can be altered through the addition of competitive HBD arrays and/or HBA anionic guests. The addition of these competitive species modifies the type of self-associative hydrogen bonding modes present between the amphiphilic molecules, triggering the in situ formation of novel hydrogen bonded nanostructures

Lipid nanoparticles for alkyl lysophospholipid edelfosine encapsulation: development and in vitro characterization

The ether lipid 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine, edelfosine (ET-18-OCH3) is the prototype molecule of a promising class of antitumour drugs named alkyl–lysophospholipid analogues (ALPs) or antitumor ether lipids. This drug presents a very important drawback as can be the dose depending haemolysis when administered intravenously. Lipid nanoparticles have been lately proposed for different drug encapsulation as an alternative to other controlled release delivery systems, such as liposomes or polymeric nanoparticles. The aim of this study was to develop a lipid nanoparticulate system that would decrease systemic toxicity as well as improve the therapeutic potential of the drug. Lipids employed were Compritol® 888 ATO and stearic acid. The nanoparticles were characterized by photon correlation spectroscopy for size and size distribution, and atomic force microscopy (AFM) was used for the determination of morphological properties. By both differential scanning calorimetry (DSC) and X-ray diffractometry, crystalline behaviour of lipids and drug was assessed. The drug encapsulation efficiency and the drug release kinetics under in vitro conditions were measured by HPLC–MS. It was concluded that Compritol® presents advantages as a matrix material for the manufacture of the nanoparticles and for the controlled release of edelfosine