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One of the most extensively used techniques inDrosophilais the Gal4/UAS binary system, which allows tissue-specific misexpression or knockdown of specific genes of interest. The original UAS vector, UASt, can only be activated for transgene expression in somatic tissues and not in the germline cells. Rørth (1998) generated UASp, a modified UAS vector that is responsive to Gal4 in both somatic and germline tissues, by replacing both thehsp70promoter and the SV40 3’UTR with the P transposase promoter and the K10 3’UTR respectively. At present, the mechanisms by which UASt is silenced in germline cells are not fully understood. Here, we report that the piRNA pathway is involved in suppressing UASt expression in ovarian germline cells. Individually knocking down or mutating components of the piRNA biogenesis pathway (e.g., Piwi, AGO3, Aub, Spn-E, and Vasa) resulted in the expression of the UASt-reporter (GFP or RFP) in the germline. An RNA-seq analysis of small RNAs revealed that thehsp70promoter of UASt is targeted by piRNAs, and in theaubmutant ovary, the amount of piRNAs targeting thehsp70promoter is reduced by around 40 folds. In contrast, the SV40 3’UTR of the UASt, which happens to be targeted by the Nonsense-mediated RNA decay (NMD) pathway, is not responsible for germline UASt suppression, as UASt-reporters with NMD-insensitive 3’UTRs fail to show germline expression. Taken together, our studies reveal a crucial role of the piRNA pathway, potentially via the suppression of thehsp70promoter, in germline UASt silencing inDrosophilaovaries.

The aim of this work is to improve the electrochemical behavior of AISI 4140 steel substrates by using a TiN[BCN/BN] n /c-BN multilayer system as a protective coating. We grew TiN[BCN/BN] n /c-BN multilayers via reactive r.f. magnetron sputtering technique, systematically varying the length period (Λ) and the bilayer number (n), maintaining constant the total thickness of the coating and all other growth parameters. The coatings were characterized by FTIR spectroscopy that showed bands associated to h-BN bonds, and c-BN stretching vibrations centered at 1385 cm − 1 and 1005 cm − 1 , respectively. Film composition was studied via X-ray photoelectron spectroscopy where typical signals for C1s, N1s and B1s are shown. The electrochemical properties were studied by electrochemical impedance spectroscopy and Tafel curves. In this work, the maximum corrosion resistance for the coating with (Λ) equal to 80 nm was obtained, corresponding to n = 25 bilayers. The polarization resistance and corrosion rate were around 10.1 kOhm cm 2 and 0.22 mm/year; these values were 83 and 15 times higher, respectively, than uncoated AISI 4140 steel substrate (0.66 kOhm cm 2 and 18.51 mm/year). Optical microscopy was used for surface analysis after corrosive attack. The improvement of the electrochemical behavior of the AISI 4140 coated with this TiN[BCN/BN] n /c-BN multilayer system can be attributed to the presence of several interfaces that offer resistance to diffusion of Cl − of the electrolyte toward the steel surface.

The aim of this work is to improve the mechanical properties of AISI 4140 steel substrates by using a TiN[BCN/BN] n /c-BN multilayer system as a protective coating. TiN[BCN/BN] n /c-BN multilayered coatings via reactive r.f. magnetron sputtering technique were grown, systematically varying the length period ( Λ ) and the number of bilayers ( n ) because one bilayer ( n = 1) represents two different layers ( t BCN + t BN ), thus the total thickness of the coating and all other growth parameters were maintained constant. The coatings were characterized by Fourier transform infrared spectroscopy showing bands associated with h-BN bonds and c-BN stretching vibrations centered at 1400 cm −1 and 1100 cm −1 , respectively. Coating composition and multilayer modulation were studied via secondary ion mass spectroscopy. Atomic force microscopy analysis revealed a reduction in grain size and roughness when the bilayer number ( n ) increased and the bilayer period decreased. Finally, enhancement of mechanical properties was determined via nanoindentation measurements. The best behavior was obtained when the bilayer period ( Λ ) was 80 nm ( n = 25), yielding the relative highest hardness (∼30 GPa) and elastic modulus (230 GPa). The values for the hardness and elastic modulus are 1.5 and 1.7 times greater than the coating with n = 1, respectively. The enhancement effects in multilayered coatings could be attributed to different mechanisms for layer formation with nanometric thickness due to the Hall–Petch effect; because this effect, originally used to explain increased hardness with decreasing grain size in bulk polycrystalline metals, has also been used to explain hardness enhancements in multilayered coatings taking into account the thickness reduction at individual single layers that make up the multilayered system. The Hall–Petch model based on dislocation motion within layered and across layer interfaces has been successfully applied to multilayered coatings to explain this hardness enhancement.

TiN/TiAlN multilayers were deposited by radio frequency, r.f., reactive magnetron sputtering by using titanium and aluminum targets with 10 cm diameter and 99.99% purity in an argon/nitrogen atmosphere, applying a substrate temperature of 300 ºC. WC inserts were used as substrates to improve the mechanical and tribological properties of TiN/TiAlN multilayered coatings compared to other types of coatings like TiAlN monolayers and to manage greater efficiency of these coatings in different industrial applications, such as machining, and extrusion. Their physical, mechanical, and tribological characteristics were investigated, including cutting tests with AISI 4340 hardened steel (50 HRC) to assess wear as a function of the period and number of bilayers. A comparison of the properties of TiCN-Al2O3-TiN monolayers coatings and the [TiN/TiAlN]300 multilayers with individual layer thicknesses of 10 nm revealed a decrease of flank wear (around 33%) for [TiN/TiAlN]300 multilayers and a reduction of flank wear (around 13%) for coatings with 300 layers when is compared with [TiN/TiAlN]200 coatings. They also showed better machining properties onto hardened AISI 4340 steel pieces, when compared to uncoated WC inserts. These results open the possibility of using [TiN/TiAlN] multilayers as new coatings for tool machining with excellent industrial performance.

Here, we present the results of a randomised clinical trial carried out between 1998 and 2004, evaluating the possible role of radiotherapy (RT) as consolidation treatment after induction chemotherapy (CT) in diffuse large B-cell (DLBC) gastric lymphoma. Fifty-four patients were enrolled and all received anthracycline containing regimens as induction CT. Patients were evaluated after four to six cycles and those in complete remission (CR) were randomised to receive gastric involved field (IF) RT or two addition cycles of the same CT. Forty-five patients (83%) were randomised after the induction CT. Clinical results of patients allocated to the RT arm showed a significant reduction in incidence of local relapse versus patients who received CT alone. However, overall survival was not different between the two arms. Our results confirm that CT could be considered as first line therapy for newly diagnosed gastric DLBC lymphoma; IF RT delivered in those patients achieving CR after induction CT is able to prevent local relapse.

Dentro del contexto social colombiano se tiene la idea de que la electrónica, especialmente aplicada a la robótica, es un tema de gran complejidad y en el que estamos rezagados. Sin embargo, esto no es del todo cierto, por lo cual se pretende mostrar que con algo inicialmente complejo para la gran mayoría como lo es un brazo robótico, se pueden realizar ciertas actividades y tareas programadas previamente, obteniendo un sistema experto. Para el caso particular de este trabajo, se diseñó e implementó un sistema con fines lúdicos capaz de desempeñar el juego de “Tres en raya” contra un oponente humano. Para tal Þ n, se tuvieron en cuenta varios aspectos tales como el discernimiento de la disposición de las Þ chas, tanto las que están dentro del tablero de juego como las que están por fuera, el planteamiento de un algoritmo capaz de establecer la mejor jugada que debe realizar el sistema artificial de forma tal que tenga la capacidad de ganarle al humano y la ejecución de los movimientos de las Þ chas por parte del sistema artificial en el juego. Todas estas consideraciones conllevan a la integración de tres áreas fundamentales: procesamiento de imágenes, algoritmia y robótica., Within the social context Colombia has the idea that electronics, especially applied to robotics, is a very complex issue and we are behind. However, this is not entirely true, which is intended to show that something initially for most complex such as a robotic arm can perform certain activities and/or preprogrammed tasks, resulting in an expert system. For the particular case of this study was designed and implemented a system able to play for fun game of Tic Tac Toe against a human opponent. For this purpose, took into account various aspects such as the perception of the willingness of both those cards in the game board as they are out, the approach of an algorithm capable of establishing the best play to be performed the artiÞ cial system in a way that has the ability to beat the man and the execution of the movements of the chips by the artiÞ cial system in the game. All these considerations lead to the integration of three key areas: image processing, algorithms and robotics.

RESUMEN: En el presente trabajo se muestran los resultados de la resistencia al desgaste de insertos de carburo de tungsteno (WC) sin recubrir y recubiertos con multinanocapas de [TiN/TiAlN]n con un espesor total promedio del recubrimiento de 4 μm, así como de insertos recubiertos con monocapas comerciales de TiCN-Al2O3-TiN (TINAL). Se realizaron ensayos de vida útil, análisis de temperatura en la zona de corte, mediciones de rugosidad superfi cial sobre la pieza y sobre los insertos en la superfi cie de ataque, análisis de huella de contacto entre viruta-insertos y análisis de composición química (EDS). Los ensayos se realizaron sobre piezas de acero AISI 4340 utilizando régimen de corte de acabado y aplicando altas velocidades de corte (HSC). Los resultados de mecanizado de acero, para un recorrido de 8.000 metros con diferentes insertos de carburo de tungsteno (WC), sin recubrimiento y recubiertos presentaron valores de desgaste de 0,117 mm y 0,138 mm; en relación a los insertos recubiertos con 300 y 200 bicapas de TiN/TiAlN, respectivamente. De igual manera, los insertos recubiertos con TINAL exhibieron valores de desgaste de 0,174 mm. Además, los valores de temperatura en la zona de corte y para una velocidad de corte de 176,6 m/mim fueron de 522,6 o C para los recubrimientos con 300 bicapas, de 721,4 o C para aquellos con 200 bicapas, y de 1.327,6 o C para los insertos recubiertos con TINAL. La disminución de la temperatura en la zona de corte, relacionada con un menor coefi ciente de fricción y una menor fuerza de corte, contribuyeron al alargamiento de la vida útil de los insertos. ABSTRACT: In the present work wear resistance of 4 μm uncoated tungsten carbide inserts (WC) and coated with [TiN/TiAlN]n multinanolayered or with commercial TiCN-Al2O3-TiN monolayers (TINAL) are examined. Life tests, cutting area temperature analysis, surface roughness measurements on work pieces, roughness measurements on the attacked surface, contact track analysis between chip-insert and chemical composition analysis (EDS) were carried out. Mechanical tests were conducted on AISI 4340 steel parts using cutting regime and applying high speed cutting (HSC). Machining results showed that for a distance of 8,000 m the inserts coated with 300 bilayers exhibited wear values of 0.117 mm, inserts coated with 200 bilayers showed values of 0.138 mm and those coated with TINAL presented wear values of 0.174 mm. Moreover, the temperature values for cutting speed at 176.6 m/mim for 300 bilayers was 522.6 o C, for 200 bilayers was 721.4 o C and 1,327.6 o C for inserts coated with TINAL. Lower temperatures, caused by a lower friction coeffi cient and cutting force, contribute to life-time increasing at WC inserts.

El objetivo del presente trabajo es introducir al lector en el área de los recubrimientos multicapa los cuales se vislumbran como una solución efectiva ante el problema del desgaste de diversas herramientas o dispositivos. Inicialmentese hace una revisión en la cual se muestran las razones que hicieron de los recubrimientos duros algo indispensable en muchos sectores industriales. A continuación se comentará acerca de los sistemas multicapa y sus bondades en cuanto al incremento de sus propiedades mecánicas para finalmente mostrardos casos reales de aplicación de este tipo de recubrimientos y los resultados obtenidos.

Dado que la evaluación física de los recubrimientos no brinda suficiente información sobre el comportamiento durante el maquinado de insertos recubiertos, en el presente trabajo se han estudiado insertos de carburo de tungsteno (WC) recubiertos con multinanocapas de [TiN/TiAlN]n (200 y 300 capas) con un espesor de 4 µm utilizando la técnica Deposición Física reactiva en fase Vapor (PVD) y comparándolas con insertos recubiertos tipo monocapa de TiCN-Al2O3-TiN (TINAL) producidas de forma industrial. Mediante esta técnica las capas depositadas están en el orden de los nanómetros.Se realizaron ensayos de temperatura mediciones de rugosidad superficial en la pieza, huella de contacto y se mostraron resultados de desgaste. Los ensayos se realizaron sobre probetas de acero AISI 4340 endurecido 50HRc aplicando altas velocidades de corte (HSC).Los valores de temperatura fueron inferiores, así para los insertos de 300 capas la disminución fue de 520 °C y para las de 200 capas de 770°C.Los resultados de los ensayos de desgaste demostraron, que los insertos recubiertos con 200 y 300 capas alcanzaron valores de vida útil mayores en un 44% y 57 % respectivamente, comparados con el valor obtenido (7600m) por el inserto de TINAL.

Here, we present the results of a randomised clinical trial carried out between 1998 and 2004, evaluating the possible role of radiotherapy (RT) as consolidation treatment after induction chemotherapy (CT) in diffuse large B-cell (DLBC) gastric lymphoma. Fifty-four patients were enrolled and all received anthracycline containing regimens as induction CT. Patients were evaluated after four to six cycles and those in complete remission (CR) were randomised to receive gastric involved field (IF) RT or two addition cycles of the same CT. Forty-five patients (83%) were randomised after the induction CT. Clinical results of patients allocated to the RT arm showed a significant reduction in incidence of local relapse versus patients who received CT alone. However, overall survival was not different between the two arms. Our results confirm that CT could be considered as first line therapy for newly diagnosed gastric DLBC lymphoma; IF RT delivered in those patients achieving CR after induction CT is able to prevent local relapse.

Con el fin de encontrar alternativas que hagan frente a los problemas que ocasiona la corrosión en algunos materiales de use cotidiano son empleados en: herramientas de mecanizado, dispositivos mecánicos, moldes de inyección y demás, se han depositado películas delgadas de Nitruro de Niobio (NbN) sobre silicio (100) y substratos de acero inoxidable AISI 304, acero rápido e insertos de WC mediante un sistema multi-blanco magnetrón sputtering con r.f. (13.56 MHz), a partir de un blanco de Nb de alta pureza (99.99%) en una atmósfera compuesta de Ar/N2. La cristalinidad de las películas crecidas fue examinada por medio de espectroscopia de difracción de rayos X (XRD). Por medio de análisis de FTIR, se encontró la presencia de modos activos alrededor de los 600 cm -1 asociados con enlaces de Nb-N. Se desarrolló la caracterización electroquímica del acero AISI 304 con y sin recubrimiento de NbN mediante espectroscopia de impedancia electroquímica (EIS) y curvas de polarización Tafel. En este trabajo se encontró que la velocidad de corrosión decrece alrededor de un 66% para el acero recubierto con NbN a OV en comparación al acero sin recubrimiento. Sin embargo, cuando el voltaje bias fue incrementado a-100V, la velocidad de corrosión es 3 veces mayor que a un voltaje de OV, lo cual muestra el efecto nocivo del voltaje en la degradación de las películas de NbN. De esta manera, se abre la posibilidad de aplicar recubrimientos basados en Nitruro de Niobio como alternativa de solución a los problemas de la corrosión de materiales., In order to find solutions to problems caused by corrosion in day -to-day materials such as mechanizing tools, mechanical devices, injection molds and the like, thin films oof NbN have been deposited on Si (100) and substrates of stainless steel AISI 304, high Speed Steel (HSS) and we inserts by using a multi-target Magnetron Sputtering system with r.f. (13.56 Mhz), from a Nb target of high purity (99.99%) in an atmosphere made up of Ar/N2. The crystalinity of the grown films was examined by X-rays diffraction (XRD) spectroscopy. By using FTIR analysis, active modes at about 600 cm associated with Nb-N bonds were found. The electrochemical characterizationg of AISI 304 steel with and without NbN covering by electrochemical impedance spectroscopy (EIS) and Tafel polirization curves. It was found also that the corrosion speed decreased about 66% for the steel covered with NbN at 0V compared to the uncovered steel. However when bias voltage was raised to -100V, the corrosion speed was three times higher, compared to the NbN covering at 0V, wich in turn shows the harmful effect of bias voltage. In the degradation of NbN films. From the results of the present study the way is now opened to the possibility of applying Nitride NbN based coatings as an alternative solution to corrosion of materials.

Este artículo analiza algunos de los problemas que presenta las tendencias demográficas españolas en la actualidad: primero, el crecimiento del gasto social relacionado con el aumento de la población no-activa; segundo, la llegada de inmigrantes desde países en desarrollo con los consiguientes problemas asociados a su situación ilegal y a la aparición de conflictos étnicos; y, por último, la pérdida de población que sufren los centros de las áreas metropolitanas que se mueven al extrarradio en busca de una mejor calidad de vida. This article analyzes some of the problems related to the actual Spanish demographic trends: first, the growing of the social burden which is due to the growing of the non-active population (non-working sector); second, the arrival of the immigrants from undeveloped countries, associated to problems such as its illegal situation in Spain or the appearance of ethnic conflicts; and third, the loss of population in the urban downtown of the metropolitan areas which moves to the suburbs looking for a better quality of life.