La comercialización de productos agropecuarios (I parte

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Torres Otavo Jorge

1984-12-01

Full Text Available La totalidad compleja que constituye la relación social de producción se descompone en partes relativamente independientes unas respecto a otras, producción - transformación - distribución - consume las cuales constituyen un sistema. Dentro del sistema de producción existe una dinámica, incluida la de poblaciones, y en su interior coexisten diversos subsistemas o subsectores como el de mercados protección de cultivos, manejo del agua, fertilización, industrialización de productos, entre otros, que viven en permanente transformación y están orgánicamente integrados al sistema de producción.

High-Density Plasma-Induced Etch Damage of GaN

International Nuclear Information System (INIS)

Baca, A.G.; Han, J.; Lester, L.F.; Pearton, S.J.; Ren, F.; Shul, R.J.; Willison, C.G.; Zhang, L.; Zolper, J.C.

1999-01-01

Anisotropic, smooth etching of the group-III nitrides has been reported at relatively high rates in high-density plasma etch systems. However, such etch results are often obtained under high de-bias and/or high plasma flux conditions where plasma induced damage can be significant. Despite the fact that the group-III nitrides have higher bonding energies than more conventional III-V compounds, plasma-induced etch damage is still a concern. Attempts to minimize such damage by reducing the ion energy or increasing the chemical activity in the plasma often result in a loss of etch rate or anisotropy which significantly limits critical dimensions and reduces the utility of the process for device applications requiring vertical etch profiles. It is therefore necessary to develop plasma etch processes which couple anisotropy for critical dimension and sidewall profile control and high etch rates with low-damage for optimum device performance. In this study we report changes in sheet resistance and contact resistance for n- and p-type GaN samples exposed to an Ar inductively coupled plasma (ICP). In general, plasma-induced damage was more sensitive to ion bombardment energies as compared to plasma flux. In addition, p-GaN was typically more sensitive to plasma-induced damage as compared to n-GaN

Central limit theorems for sequences with m(n)-dependent main part

NARCIS (Netherlands)

Nieuwenhuis, G.

1992-01-01

Let (Xi(n); n ϵ N, 1⩽i⩽h(n)) be a double sequence of random variables with h(n)→∞ as n→∞. Suppose that the sequence can be split into two parts: an m(n)-dependent sequence (Xi,m(n); n ϵ N, 1⩽i⩽h(n)) of main terms and a sequence (Xi,m(n); n ϵ N, 1⩽i⩽h(n)) of residual terms. Here (m(n)) may be

Una fórmula que relaciona a los números primos con la función parte entera y los números triangulares

OpenAIRE

Braddock S., George

2014-01-01

El máximo común divisor entre un número primo p y cada uno de los enteros positivos menores que p es igual a 1 y, como el máximo común divisor se relaciona con la función parte entera según una fórmula explícita dada por el matemático brasileño M. Polezzi (1997), entonces se halló una interesante proposición que relaciona los números primos, la función parte entera, los números cuadrados y los números triangulares. Esa proposición sirve como un nuevo test para probar la primalidad de un númer...

Parts harvendas ootamatult Eesti Energia nõukogu / Andres Eilart

Index Scriptorium Estoniae

Eilart, Andres

2011-01-01

Majandus- ja kommunikatsiooniminister Juhan Parts otsustas 1. juulil päevapealt Eesti Energia nõukogu liikme kohalt tagasi kutsuda Aivar Reiviku ning Rein Kuusmiku, kes olid vastu Eesti Energia üle viie miljoni euro suurusele investeeringule Weroli rapsiõlitehase juurde rajatavasse elektri- ja küttejaama. Uuteks nõukogu liikmeteks said Andres Saame ja Toomas Tauts

Involvement of mismatch repair proteins in adaptive responses induced by N-methyl-N'-nitro-N-nitrosoguanidine against {gamma}-induced genotoxicity in human cells

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Ayumi; Sakamoto, Yasuteru; Masumura, Kenichi; Honma, Masamitsu [Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Nohmi, Takehiko, E-mail: nohmi@nihs.go.jp [Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan)

2011-08-01

Highlights: {yields} Health effects of radiation should be evaluated in combination with chemicals. {yields} Here, we show that MNNG suppresses radiation-induced genotoxicity in human cells. {yields} Mismatch repair proteins play critical roles in the apparent adaptive responses. {yields} Chemical exposure may modulate radiation-induced genotoxicity in humans. - Abstract: As humans are exposed to a variety of chemical agents as well as radiation, health effects of radiation should be evaluated in combination with chemicals. To explore combined genotoxic effects of radiation and chemicals, we examined modulating effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a direct-acting methylating agent, against genotoxicity of {gamma}-radiation. Human lymphoblastoid TK6 cells and its mismatch-deficient derivative, i.e., MT1 cells, were treated with MNNG for 24 h before they were exposed to {gamma}-irradiation at a dose of 1.0 Gy, and the resulting genotoxicity was examined. In TK6 cells, the pretreatments with MNNG at low doses suppressed frequencies of the thymidine kinase (TK) gene mutation and micronucleus (MN) formation induced by {gamma}-irradiation and thus the dose responses of TK and MN assays were U-shaped along with the pretreatment doses of MNNG. In contrast, the genotoxic effects of MNNG and {gamma}-irradiation were additive in MT1 cells and the frequencies of TK mutations and MN induction increased along with the doses of MNNG. Apoptosis induced by {gamma}-radiation was suppressed by the pretreatments in TK6 cells, but not in MT1 cells. The expression of p53 was induced and cell cycle was delayed at G2/M phase in TK6, but not in MT1 cells, by the treatments with MNNG. These results suggest that pretreatments of MNNG at low doses suppress genotoxicity of {gamma}-radiation in human cells and also that mismatch repair proteins are involved in the apparent adaptive responses.

NUEVO CALENDARIO DE VACUNACIÓN PARA ESPAÑA, 2016 (PARTE 1

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Aurora Limia-Sánchez

2016-01-01

Full Text Available El calendario de vacunación en España es una herramienta dinámica de salud pública que ha ido incorporando cambios en función de la situación epidemiológica y la evidencia científica. La Ponencia del Programa y Registro de Vacunaciones, órgano científico-técnico del Consejo Interterritorial del Sistema Nacional de Salud, realiza evaluaciones y propone modificacio - nes que se incorporan en el calendario de vacunación de las comunidades autónomas (CCAA. Este artículo está dividido en dos partes y presenta la evaluación realizada para proponer un nuevo esquema de vacunación frente a difteria, tétanos, tosferina, poliomielitis, hepatitis B y enfermedad invaso - ra por Haemophilus influenzae tipo b, centrándose esta primera parte en la exposición de motivos, el repaso a la política de vacunación en España y su impacto así como en la revisión de los calendarios de vacunación en países de nuestro entorno.

Juhan Parts : näoga tuleviku poole / Juhan Parts ; interv. Märt Kivine

Index Scriptorium Estoniae

Parts, Juhan, 1966-

2005-01-01

Res Publica esimehe kohalt lahkuv Juhan Parts ütleb, et erakond on jäänud endaks - ausaks. Res Publica praeguse seisu üks põhjusi on tema arvates see, et erakond pole võtnud omaks vana poliitika lähenemisviise, ükski olemasolev erakond ei taha näha Res Publicat Eesti poliitikas. Lisa: Res Publica valib uue juhi

Costs of jasmonic acid induced defense in aboveground and belowground parts of corn (Zea mays L.).

Science.gov (United States)

Feng, Yuanjiao; Wang, Jianwu; Luo, Shiming; Fan, Huizhi; Jin, Qiong

2012-08-01

Costs of jasmonic acid (JA) induced plant defense have gained increasing attention. In this study, JA was applied continuously to the aboveground (AG) or belowground (BG) parts, or AG plus BG parts of corn (Zea mays L.) to investigate whether JA exposure in one part of the plant would affect defense responses in another part, and whether or not JA induced defense would incur allocation costs. The results indicated that continuous JA application to AG parts systemically affected the quantities of defense chemicals in the roots, and vice versa. Quantities of DIMBOA and total amounts of phenolic compounds in leaves or roots generally increased 2 or 4 wk after the JA treatment to different plant parts. In the first 2 wk after application, the increase of defense chemicals in leaves and roots was accompanied by a significant decrease of root length, root surface area, and root biomass. Four weeks after the JA application, however, no such costs for the increase of defense chemicals in leaves and roots were detected. Instead, shoot biomass and root biomass increased. The results suggest that JA as a defense signal can be transferred from AG parts to BG parts of corn, and vice versa. Costs for induced defense elicited by continuous JA application were found in the early 2 wk, while distinct benefits were observed later, i.e., 4 wk after JA treatment.

Inductively coupled plasma-induced defects in n-type GaN studied from Schottky diode characteristics

International Nuclear Information System (INIS)

Nakamura, W.; Tokuda, Y.; Ueda, H.; Kachi, T.

2006-01-01

Inductively coupled plasma-(ICP-)induced defects in n-type GaN have been studied from current-voltage (I-V) characteristics and deep-level transient spectroscopy (DLTS) for Schottky diodes fabricated on etched surfaces. The samples after ICP etching show the ohmic I-V characteristics. Schottky characteristics are obtained after annealing at 600 and 800 deg. C in N 2 , but are not restored to that of the control samples. DLTS shows that the effect of ICP etching is small on the region beyond 80 nm from the surface. These results suggest that there remain ICP-induced damage in the near-surface region after thermal annealing

Hole-induced d"0 ferromagnetism enhanced by Na-doping in GaN

International Nuclear Information System (INIS)

Zhang, Yong; Li, Feng

2017-01-01

The d"0 ferromagnetism in wurtzite GaN is investigated by the first-principle calculations. It is found that spontaneous magnetization occurs if sufficient holes are injected in GaN. Both Ga vacancy and Na doping can introduce holes into GaN. However, Ga vacancy has a high formation energy, and is thus unlikely to occur in a significant concentration. In contrast, Na doping has relatively low formation energy. Under N-rich growth condition, Na doping with a sufficient concentration can be achieved, which can induce half-metallic ferromagnetism in GaN. Moreover, the estimated Curie temperature of Na-doped GaN is well above the room temperature. - Highlights: • Hole-induced ferromagnetism in GaN is confirmed. • Both Ga Vacancy and Na-doping can introduce hole into GaN. • The concentration of Ga vacancy is too low to induce detectable ferromagnetism. • Na-doped GaN is a possible ferromagnet with a high curie-temperature.

Organising pneumonia due to dronedarone.

Science.gov (United States)

Thornton, D; Avery, S; Edey, A J; Medford, A R L

2015-01-01

Organising pneumonia is one of the responses of the lung to injury and can mimic bacterial pneumonia but importantly it does not respond to antibiotic therapy. We present the case of a 67-year-old male who was diagnosed with organising pneumonia secondary to dronedarone. Drug reactions are a common cause and early identification of the culprit is mandatory to prevent further morbidity and ensure a favourable outcome. On chest radiography there may be fleeting peripheral consolidation, while computed tomography can show a range of stereotyped patterns including perilobular consolidation. Bronchoscopic biopsy may not always be possible but response to steroids is often rapid following removal of the culprit drug. Dronedarone should be included in the list of possible drugs and the Pneumotox database remains a useful resource for the clinician when acute drug-related pneumotoxicity is suspected.

Historia de la Conservación Preventiva. Parte II

OpenAIRE

García Fernández, Isabel M.

2014-01-01

La segunda parte de la historia de la conservación preventiva comienza en 1990; esta etapa es mucho más corta que la primera,pero más prolífica en materiales, proyectos y publicaciones. Vamos a ver cómo desde sus inicios, la conservación preventiva ha ido cobrando protagonismo en todos los ámbitos relacionados con la preservación y uso del patrimonio. En este artículo vamos a destacar los hitos fundamentales que han conseguido afianzar esta disciplina en los últimos 25 años y valorar- su desa...

Doxycycline attenuates acrolein-induced mucin production, in part by inhibiting MMP-9.

Science.gov (United States)

Ren, Shuang; Guo, Ling-Li; Yang, Jie; Liu, Dai-Shun; Wang, Tao; Chen, Lei; Chen, Ya-Juan; Xu, Dan; Feng, Yu-Lin; Wen, Fu-Qiang

2011-01-10

Matrix metalloproteinases (MMPs), especially MMP-9, have been found to increase the expression of epidermal growth factor (EGF) receptor, a possible regulator of acrolein-induced mucin expression in the airway epithelium. The aim of this study was to investigate whether doxycycline, a tetracycline antibiotic that inhibits MMPs, attenuates mucus production and synthesis of mucin MUC5AC in acrolein-exposed rats. Sprague-Dawley rats were exposed to acrolein aerosol [3.0parts/million (ppm), 6h/day, 12days] and they received 20mg/kg doxycycline daily by gavage, beginning two days before exposure to acrolein until the end of the experiment. The production of mucin glycoproteins and expression of the MMP-9 and MUC5AC genes were measured in rat trachea. The increase in levels of MMP-9 mRNA and protein in airway epithelium after acrolein exposure was accompanied by an increase in MUC5AC mRNA expression. Doxycycline significantly prevented these increases in acrolein-induced expression of MMP-9 and MUC5AC and attenuated mucus production in tracheal epithelium. These results indicate that doxycycline attenuated acrolein-induced mucin synthesis, in part by inhibiting expression of MMP-9. Thus doxycycline may have a prophylactic effect in the treatment of smoking-induced mucus hypersecretion. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

Activation measurements for fast neutrons. Part D. Evaluation of cosmic-ray-induced 63Ni background in copper

International Nuclear Information System (INIS)

Ruehm, Werner; Rugel, Georg; Faestermann, Thomas

2005-01-01

As a result of a joint collaboration between the University of Utah, LLNL, the Technical University Munich and the Ludwig Maximilians University Munich, it became possible to determine A-bomb induced 63 Ni in pure copper samples from Hiroshima beyond a ground range of 1,000 m (see Chapter 9, Part B). The low 63 Ni activities induced in copper samples due to neutrons from the A-bomb explosion at large distance require, however, a careful discussion of the fraction of 63 Ni produced in these samples due to cosmic radiation. In this section, an analysis of the production of 63 Ni in copper samples due to cosmic radiation is performed. Production due to neutrons, protons, stopped muons, and photonuclear reactions is discussed. It is obvious from Figure 1 (Pfennig et al. 1995) that a variety of reactions induced by neutrons, protons, muons and photons can contribute to the production of 63 Ni in copper. The most important of these processes will be discussed here. Since the cross-sections for the production of 63 Ni in copper samples due to fast and stopped muons were not known, they were determined experimentally. (J.P.N.)

UV-induced N2O emission from plants

Science.gov (United States)

Bruhn, Dan; Albert, Kristian R.; Mikkelsen, Teis N.; Ambus, Per

2014-12-01

Nitrous oxide (N2O) is an important long-lived greenhouse gas and precursor of stratospheric ozone-depleting mono-nitrogen oxides. The atmospheric concentration of N2O is persistently increasing; however, large uncertainties are associated with the distinct source strengths. Here we investigate for the first time N2O emission from terrestrial vegetation in response to natural solar ultra violet radiation. We conducted field site measurements to investigate N2O atmosphere exchange from grass vegetation exposed to solar irradiance with and without UV-screening. Further laboratory tests were conducted with a range of species to study the controls and possible loci of UV-induced N2O emission from plants. Plants released N2O in response to natural sunlight at rates of c. 20-50 nmol m-2h-1, mostly due to the UV component. The emission response to UV-A is of the same magnitude as that to UV-B. Therefore, UV-A is more important than UV-B given the natural UV-spectrum at Earth's surface. Plants also emitted N2O in darkness, although at reduced rates. The emission rate is temperature dependent with a rather high activation energy indicative for an abiotic process. The prevailing zone for the N2O formation appears to be at the very surface of leaves. However, only c. 26% of the UV-induced N2O appears to originate from plant-N. Further, the process is dependent on atmospheric oxygen concentration. Our work demonstrates that ecosystem emission of the important greenhouse gas, N2O, may be up to c. 30% higher than hitherto assumed.

Sleep-inducing N-alkyl-5-[m-(trifluoromethyl)phenyl]-5-hydroxy-2-pyrrolidinones and N-alkyl-3-(trifluoromethyl)cinnamamides.

Science.gov (United States)

Houlihan, W J; Gogerty, J H; Ryan, E A; Schmitt, G

1985-01-01

A series of N-alkyl-3-[m-(trifluoromethyl)phenyl]-5-hydroxy-2-pyrrolidinones and N-alkyl-3-(trifluoromethyl)-cinnamamides were prepared and screened in a series of tests designed to detect potential sleep inducers. The more active members of the series were evaluated for their ability to induce sleep in Cebus monkeys. The most active compound, N-methyl-5-[m-(trifluoromethyl)phenyl]-5-hydroxy-2-pyrrolidinone, was equal to methaqualone.

N-Acetylcysteine reverses cocaine-induced metaplasticity.

Science.gov (United States)

Moussawi, Khaled; Pacchioni, Alejandra; Moran, Megan; Olive, M Foster; Gass, Justin T; Lavin, Antonieta; Kalivas, Peter W

2009-02-01

Cocaine addiction is characterized by an impaired ability to develop adaptive behaviors that can compete with cocaine seeking, implying a deficit in the ability to induce plasticity in cortico-accumbens circuitry crucial for regulating motivated behavior. We found that rats withdrawn from cocaine self-administration had a marked in vivo deficit in the ability to develop long-term potentiation (LTP) and long-term depression (LTD) in the nucleus accumbens core subregion after stimulation of the prefrontal cortex. N-acetylcysteine (NAC) treatment prevents relapse in animal models and craving in humans by activating cystine-glutamate exchange and thereby stimulating extrasynaptic metabotropic glutamate receptors (mGluR). NAC treatment of rats restored the ability to induce LTP and LTD by indirectly stimulating mGluR2/3 and mGluR5, respectively. Our findings show that cocaine self-administration induces metaplasticity that inhibits further induction of synaptic plasticity, and this impairment can be reversed by NAC, a drug that also prevents relapse.

Percepción del cuidado por parte del cuidador familiar

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Isabel Fernández Lao

2013-06-01

Full Text Available Objetivo principal: Determinar el significado del cuidado en el cuidador familiar. Metodología: Estudio cualitativo, fenomenológico, descriptivo, con grupo focal, 14 cuidadoras pertenecientes a la Unidad de Gestión Clínica Almería Centro. Análisis de contenido, trascripción, segmentación, codificación y clasificación en categorías del texto. Resultados principales. Categorías: tareas, valores, reconocimiento (familiar, profesional, institucional, apoyo al cuidado, medidas de mejora. Conclusión principal: En el cuidado prima la obligación moral, especialmente en caso de la mujer, escasamente reconocido, especialmente por la persona cuidada, pese a medidas adoptadas las cuidadoras reclaman más información y captación activa por parte del personal de enfermería.

EPR study of N+-ion-induced free radical formation in antibiotic-producers

International Nuclear Information System (INIS)

Xie Liqing; Zhang Yinfen; Chen Ruyi; Gao Juncheng; Zhang Peiling; Ying Hengfeng.

1995-01-01

Under the room temperature, electron paramagnetic resonance (EPR) spectrometer was used to study free radical formation in antibiotic-producers in order to investigate antibiotic-producer mutagenic breeding, which were induced by N + ion implanting into antibiotic-producers (e.g., Streptomyces ribosidificus, Streptomyces kanamyceticus and the phage-resistant culture of Streptomyces kanamyceticus). The results show that a lot of free radicals can be induced by N + ion implanting into antibiotic-producers, and the yields of the free radicals increase with implanting dose. The death rate of antibiotic-producers rises due to the increase of N + -ion-induced free radical yields. (author)

LA MEDIACIÓN FAMILIAR. EL ENCUENTRO DE LAS PARTES COMO APERTURA A LA TRANSFORMACIÓN

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Miguel Ángel Montoya Sánchez

2012-11-01

Full Text Available En el presente escrito, se delinean algunos de los hallazgos atinentes a los objetivos trazados en la investigación referida, en especial, los que se centraronen el concepto de la transformación en el tratamiento de los conflictos de familia1. Para ello, se arrimaron a la investigación, además de la opinión de expertos, la descripción y contrastación de la percepción de quienes como partes intervinieron en los encuentros de mediación realizados. En el texto se hace referencia igualmente, a los conflictos de pareja y de familia, relievando lasdiferencias y semejanzas que estos presentan al momento de su génesis y de sutratamiento; se pone de manifiesto, asimismo, el concepto de mediación familiar,desde el cual se acentúan, finalmente, los elementos que ofrecen la posibilidad de la transformación de los conflictos y de las relaciones de familia.

Curcumin Attenuates N-Nitrosodiethylamine-Induced Liver Injury in Mice by Utilizing the Method of Metabonomics.

Science.gov (United States)

Qiu, Peiyu; Sun, Jiachen; Man, Shuli; Yang, He; Ma, Long; Yu, Peng; Gao, Wenyuan

2017-03-08

N-Nitrosodiethylamine (DEN) exists as a food additive in cheddar cheese, processed meats, beer, water, and so forth. It is a potent hepatocarcinogen in animals and humans. Curcumin as a natural dietary compound decreased DEN-induced hepatocarcinogenesis in this research. According to the histopathological examination of liver tissues and biomarker detection in serum and livers, it was demonstrated that curcumin attenuated DEN-induced hepatocarcinogenesis through parts of regulating the oxidant stress enzymes (T-SOD and CAT), liver function (ALT and AST) and LDHA, AFP level, and COX-2/PGE2 pathway. Furthermore, curcumin attenuated metabolic disorders via increasing concentration of glucose and fructose, and decreasing levels of glycine and proline, and mRNA expression of GLUT1, PKM and FASN. Docking study indicated that curcumin presented strong affinity with key metabolism enzymes such as GLUT1, PKM, FASN and LDHA. There were a number of amino acid residues involved in curcumin-targeting enzymes of hydrogen bonds and hydrophobic interactions. All in all, curcumin exhibited a potent liver protective agent inhibiting chemically induced liver injury through suppressing liver cellular metabolism in the prospective application.

INTEGRACIÓN ESTRATÉGICA: EL PROYECTO DE CAMBIO. PARTE II

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Colectivo de autores

2007-05-01

Full Text Available Este artículo constituye la segunda parte de "Dirección estratégica integrada Conceptualización". Ambos describen la experiencia realizada en la Empresa Astilleros del Caribe (Asticar por un equipo de profesores del Instituto Superior Politécnico José Antonio Echeverría, junto a dirigentes y trabajadores de la empresa, en la introducción de una iniciativa de perfeccionamiento de la gestión empresarial denominada por el grupo de consultores norteamericanos como integración estratégica. El primer artículo trata el diagnóstico del nivel de integración estratégica LIF, conteniendo el procedimiento general de diagnóstico, los instrumentos, la plataforma para gestionar integralmente el proceso de cambio y los resultados de su aplicación en la empresa. En este segundo artículo, se presenta el proyecto de cambio para elevar el nivel de integración estratégica LIF en Asticar.

nNOS inhibitors attenuate methamphetamine-induced dopaminergic neurotoxicity but not hyperthermia in mice.

Science.gov (United States)

Itzhak, Y; Martin, J L; Ail, S F

2000-09-11

Methamphetamine (METH)-induced dopaminergic neurotoxicity is associated with hyperthermia. We investigated the effect of several neuronal nitric oxide synthase (nNOS) inhibitors on METH-induced hyperthermia and striatal dopaminergic neurotoxicity. Administration of METH (5 mg/kg; q. 3 h x 3) to Swiss Webster mice produced marked hyperthermia and 50-60% depletion of striatal dopaminergic markers 72 h after METH administration. Pretreatment with the nNOS inhibitors S-methylthiocitrulline (SMTC; 10 mg/kg) or 3-bromo-7-nitroindazole (3-Br-7-NI; 20 mg/kg) before each METH injection did not affect the persistent hyperthermia produced by METH, but afforded protection against the depletion of dopaminergic markers. A low dose (25 mg/kg) of the nNOS inhibitor 7-nitroindazole (7-NI) did not affect METH-induced hyperthermia, but a high dose (50 mg/kg) produced significant hypothermia. These findings indicate that low dose of selective nNOS inhibitors protect against METH-induced neurotoxicity with no effect on body temperature and support the hypothesis that nitric oxide (NO) and peroxynitrite have a major role in METH-induced dopaminergic neurotoxicity.

Simultaneous determination of 14N and 15N isotopes in opium by proton induced γ-ray emission technique

International Nuclear Information System (INIS)

Pritty Rao; Reddy, G.L.N.; Vikram Kumar, S.; Ramana, J.V.; Raju, V.S.; Sanjiv Kumar

2012-01-01

The paper describes the simultaneous determination of 14 N and 15 N isotopes in opium by proton induced γ-ray emission (PIGE) technique. The isotopic ratio of 14 N and 15 N is a useful parameter for assigning provenance of (seized) illicit drugs. The measurement, non-destructive in nature, is performed on pellets made up of opium powders and is based on the prompt detection of 2.313 and 4.4 MeV γ-rays emanating from 14 N(p,p'γ) 14 N and 15 N(p,αγ) 12 C nuclear reactions respectively, induced simultaneously by 3.6-3.8 MeV proton beam. Positive as well as negative deviations from the natural isotopic abundance (99.63:0.37) were observed in the samples. The precision of the measurements is about 4%. The methodology provides an easy and rapid approach to determine the isotopic ratio of 14 N and 15 N and has been used for the first time in the analysis of opium. (author)

Materiales compuestos de matriz metálica. II parte. Métodos de procesado y consolidación de MMCs reforzados con partículas

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Edil da Costa, Cesar

2000-06-01

Full Text Available This work is a review of the different forming and consolidation methods for particulate metal matrix composites. In the first part we focus in the forming methods from raw materials while the second is centred in the consolidation from preforms in order to get the final part.

En este trabajo se ofrece una revisión de los distintos métodos de conformado y consolidación de materiales compuestos de matriz metálica reforzados con partículas. En una primera parte se hace hincapié en los métodos de conformado a partir de las materias primas y en la segunda en métodos de consolidación final a partir de preformas.

The role of multiple dopamine receptors in apomorphine and N-n-propylnorapomorphine-induced climbing and hypothermia.

Science.gov (United States)

Moore, N A; Axton, M S

1990-03-20

Apomorphine and N-n-propylnorapomorphine (NPA) were compared for their ability to induce stereotyped cage climbing and hypothermia in mice. Climbing behavior was produced by similar doses of apomorphine and NPA (0.625-2.5 mg/kg s.c.), whereas NPA was 43 times more potent than apomorphine in inducing a hypothermic response. SKF38393 caused a shift to the left in the dose-response curve for NPA-induced climbing, the ED50 changing from 0.98 to 0.014 mg/kg. SKF38393 had no effect on apomorphine-induced climbing behaviour. The climbing response produced by apomorphine was antagonised by both D-1 and D-2 antagonists. Climbing behaviour induced by NPA (2.5 mg/kg) could be antagonised by SCH23390 but not by clebopride, however climbing behaviour induced by a low dose of NPA (0.06 mg/kg) plus SKF38393 could be blocked by both D-1 and D-2 receptor antagonists. The hypothermic responses produced by either apomorphine or NPA could only be reversed by the selective D-2 antagonist, clebopride. These results demonstrate that dopamine agonist-induced stereotyped cage climbing requires both D-1 and D-2 receptor stimulation, whereas the hypothermic response is D-2-mediated. The results also show that it is possible to assess the relative activity of a dopamine agonist at D-1 or D-2 receptors in vivo by comparing the ability of the compound to induce hypothermia and climbing behaviour.

Antibacterianos de acción sistémica: Parte III. Sulfonamidas y tetraciclinas

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Manuel Cué Brugueras

1999-04-01

Full Text Available Resumen: Se presenta la tercera parte de una revisión bibliográfica sobre los antibacterianos de elección, en la cual se abordan los grupos sulfonamidas y tetraciclinas; además, se incluye un cuadro resumen con los antibióticos tratados en las tres partes, así como sus vías de administración y nombres comerciales que se utilizan en Cuba. Se hacen algunas consideraciones sobre la manera de enfrentar la gran variedad de antibióticos y el costo de la antibióticoterapia por parte de los países en vías de desarrollo, tomando como referencia algunas recomendaciones hechas por la OPS/OMSSummary: The third part of a bibliographic review on the elective antibacterials in which the groups of sulfonamides and tetracyclines are approached is presented. It is also included a summary picture with the antibiotics dealt with in the three parts, the routes of administration, and the trade names used in Cuba. Some considerations are made on the way to face the wide range of antibiotics and the cost of antibiotic therapy in the developing countries, taking into account some recommendations made by the PAHO/WHO

DNA compaction in the early part of the SOS response is dependent on RecN and RecA.

Science.gov (United States)

Odsbu, Ingvild; Skarstad, Kirsten

2014-05-01

The nucleoids of undamaged Escherichia coli cells have a characteristic shape and number, which is dependent on the growth medium. Upon induction of the SOS response by a low dose of UV irradiation an extensive reorganization of the nucleoids occurred. Two distinct phases were observed by fluorescence microscopy. First, the nucleoids were found to change shape and fuse into compact structures at midcell. The compaction of the nucleoids lasted for 10-20 min and was followed by a phase where the DNA was dispersed throughout the cells. This second phase lasted for ~1 h. The compaction was found to be dependent on the recombination proteins RecA, RecO and RecR as well as the SOS-inducible, SMC (structural maintenance of chromosomes)-like protein RecN. RecN protein is produced in high amounts during the first part of the SOS response. It is possible that the RecN-mediated 'compact DNA' stage at the beginning of the SOS response serves to stabilize damaged DNA prior to recombination and repair.

Percepción de los afroamericanos por parte del migrante laboral mexicano en Estados Unidos

OpenAIRE

Ricardo CONTRERAS-SOTO; Roberto HERNÁNDEZ-SAMPIERI

2011-01-01

La presente investigación forma parte de un estudio más amplio donde se analiza la percepción de distintas alteridades por parte de inmigrantes mexicanos en Estados Unidos, con testimonios de 1 265 migrantes procedentes principalmente de la región del corredor industrial abajeño de Guanajuato. El tratamiento de la información por medio de entrevistas se apoya en la hermenéutica profunda. Los testimonios directos sobre identidades culturales suman 76 casos, que conforman seis por ciento de ...

El turismo cultural: gestión de partes interesadas y la complejidad del equilibrio

Directory of Open Access Journals (Sweden)

Alfredo Ascanio

2009-01-01

Full Text Available El equilibrio del desarrollo sostenible es posible siempre que las partes interesadas colaboren entre sí. Durante 1999 comenzó el desarrollo de un modelo normativo de planificación turística basado en la coordinación de los intereses de los actores del turismo. Esta herramienta lograría equilibrar los intereses de las partes implicadas y sus servicios. Ello supone implantar una estrategia de segmentación, como fue sugerido por los expertos en marketing turístico Elise Truly Sautter y Birgit Leisen.

Comunicación de masas y producción de ideología (1era Parte

Directory of Open Access Journals (Sweden)

Eliseo Verón

2015-05-01

El estudio, además, se refiere a la conceptualización de las condiciones de producción de los textos. Esta conceptualización preside la definición de una lectura ideológica posible de esos textos. Desde este punto de vista, un análisis de textos orientado al estudio de lo ideológico en el seno del "discurso", debe ser encuadrado por un conjunto de hipótesis externas que permiten constituir el "corpus", por un lado y, por otro, detectar operaciones pertinentes dentro de él. Lo cual significa que la presencia de lo ideológico en el discurso no consiste en propiedades inmanentes a los textos, sino en un sistema de relaciones entre el texto, por una parte y su producción, su circulación y su consumo, por otra.

Photocurrent characteristics of metal–AlGaN/GaN Schottky-on-heterojunction diodes induced by GaN interband excitation

Science.gov (United States)

Tang, Xi; Li, Baikui; Chen, Kevin J.; Wang, Jiannong

2018-05-01

The photocurrent characteristics of metal–AlGaN/GaN Schottky-on-heterojunction diodes were investigated. When the photon energy of incident light was larger than the bandgap of GaN but smaller than that of AlGaN, the alternating-current (ac) photocurrent measured using lock-in techniques increased with the chopper frequency. Analyzing the generation and flow processes of photocarriers revealed that the photocurrent induced by GaN interband excitation featured a transient behavior, and its direction reversed when the light excitation was removed. The abnormal dependence of the measured ac photocurrent magnitude on the chopper frequency was explained considering the detection principles of a lock-in amplifier.

Estudio de la granulación de la mezcla de minerales de hierro en el proceso de sinterización. I parte. Granulación

Directory of Open Access Journals (Sweden)

Formoso, Antonio

2000-08-01

Full Text Available The granulation process of the ore mixture is described and the fitness for granulation of several iron ores form part of the mixture is studied. With a good granulation and sintering maximum temperature control is possible to achieve the best sintered structure, forming by a hematite nucleous bonded by acicular ferrites. The industrial experience of several types of granulation is described.

Se describe el proceso de granulación de la mezcla de mineral y se estudia la aptitud a la granulación de una serie de minerales de hierro que forman parte de la mezcla. Con una buena granulación y control de la temperatura máxima de sinterización, se puede conseguir la estructura óptima del sintetizado, formada por un núcleo de hematita rodeado por una red de ferritos aciculares. Se expone la práctica industrial de distintas formas de realizar la granulación.

Investigation of the current collapse induced in InGaN back barrier AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Wan Xiaojia; Wang Xiaoliang; Xiao Hongling; Feng Chun; Jiang Lijuan; Qu Shenqi; Wang Zhanguo; Hou Xun

2013-01-01

Current collapses were studied, which were observed in AlGaN/GaN high electron mobility transistors (HEMTs) with and without InGaN back barrier (BB) as a result of short-term bias stress. More serious drain current collapses were observed in InGaN BB AlGaN/GaN HEMTs compared with the traditional HEMTs. The results indicate that the defects and surface states induced by the InGaN BB layer may enhance the current collapse. The surface states may be the primary mechanism of the origination of current collapse in AlGaN/GaN HEMTs for short-term direct current stress. (semiconductor devices)

Inducible hydrogenase in cyanobacteria enhances N/sub 2/ fixation. [Nostoc, anabaena

Energy Technology Data Exchange (ETDEWEB)

Tel-Or, E.; Luijk, L.W.; Packer, L.

1977-06-01

Whether hydrogenase is activated or induced, we found no evidence for activation of either consumption or production of H/sub 2/ in aerobically-grown cultures but both of these activities increased 5--20-fold when cultures are grown under H/sub 2/ gas. On the other hand, hydrogenase-catalyzed consumption of H/sub 2/ is stimulated by light and/or light plus CO/sub 2/ in hydrogenase-induced cultures. Nitrogenase activity appears to be induced in cultures grown under H/sub 2/. Studies unambiguously establish that in H/sub 2/-induced cultures hydrogenase manifests a cooperativity with nitrogenase. In the presence of H/sub 2/ the activity of nitrogenase is stimulated 3--5-fold such that rates of about 3 ..mu..mol N/sub 2/ fixed/mg chlorophyll/h are obtained if the method of Peterson and Burris is used to convert acetylene reduction data to equivalents of /sup 15/N/sub 2/ fixation to ammonia.

Preventive effects of fructose and N-acetyl-L-cysteine against cytotoxicity induced by the psychoactive compounds N-methyl-5-(2-aminopropyl)benzofuran and 3,4-methylenedioxy-N-methamphetamine in isolated rat hepatocytes.

Science.gov (United States)

Nakagawa, Yoshio; Suzuki, Toshinari; Inomata, Akiko

2018-02-01

Psychoactive compounds, N-methyl-5-(2-aminopropyl)benzofuran (5-MAPB) and 3,4-methylenedioxy-N-methamphetamine (MDMA), are known to be hepatotoxic in humans and/or experimental animals. As previous studies suggested that these compounds elicited cytotoxicity via mitochondrial dysfunction and/or oxidative stress in rat hepatocytes, the protective effects of fructose and N-acetyl-l-cysteine (NAC) on 5-MAPB- and MDMA-induced toxicity were studied in rat hepatocytes. These drugs caused not only concentration-dependent (0-4 mm) and time-dependent (0-3 hours) cell death accompanied by the depletion of cellular levels of adenosine triphosphate (ATP) and glutathione (reduced form; GSH) but also an increase in the oxidized form of GSH. The toxic effects of 5-MAPB were greater than those of MDMA. Pretreatment of hepatocytes with either fructose at a concentration of 10 mm or NAC at a concentration of 2.5 mm prevented 5-MAPB-/MDMA-induced cytotoxicity. In addition, the exposure of hepatocytes to 5-MAPB/MDMA caused the loss of mitochondrial membrane potential, although the preventive effect of fructose was weaker than that of NAC. These results suggest that: (1) 5-MAPB-/MDMA-induced cytotoxicity is linked to mitochondrial failure and depletion of cellular GSH; (2) insufficient cellular ATP levels derived from mitochondrial dysfunction were ameliorated, at least in part, by the addition of fructose; and (3) GSH loss via oxidative stress was prevented by NAC. Taken collectively, these results indicate that the onset of toxic effects caused by 5-MAPB/MDMA may be partially attributable to cellular energy stress as well as oxidative stress. Copyright © 2017 John Wiley & Sons, Ltd.

Modelado y generación del Prototipo Virtual de una máquina calibradora para la inspección de fruta en postcosecha. Simulación de funcionamiento de sus partes móviles

OpenAIRE

TORMO SOLER, EDUARDO

2015-01-01

[ES] Las tareas a realizar serían, usando la aplicación de modelado Inventor/Solidworks: ¿Elaboración de los modelos 3D de todas las partes básicas de la máquina de inspección. ¿Generación del prototipo virtual de la máquina. ¿Generación de los planos. ¿Simulación de las partes móviles. Tormo Soler, E. (2015). Modelado y generación del Prototipo Virtual de una máquina calibradora para la inspección de fruta en postcosecha. Simulación de funcionamiento de sus partes móviles....

The induced expression of heat shock proteins as a part of the early cellular response to gamma radiation

International Nuclear Information System (INIS)

Stankova, K.; Ivanova, K.; Georgieva, R.; Rupova, I.; Boteva, R.

2008-01-01

A variety of stressful stimuli including gamma radiation can induce increase in the synthesis of heat shock proteins (Hsp). This family of molecular chaperones includes members with molecular masses ranging from 10 to 150 kDa and has been identified in all organisms from bacteria to humans. Hsp70 chaperones are very important. The present study aimed to characterize the radiation-induced changes in Hsp70 synthesis in human lymphocytes as a part of the early cellular response to gamma irradiation. The expression of Hsp70 was determined with Western blot and the radiation-induced apoptotic changes were registered by staining with fluorescent dyes. Part of the experiments were performed in the presence of the organic solvent DMSO. At low concentrations this reagent shows antioxidant activity and can reduce the level of the radiation-induced oxidant stress which determines the predominant biological effects of the ionizing radiation. Irradiation with 0.5 to 8 Gy caused statistically significant increase in the synthesis of Hsp70 which was strongest after irradiation with 4 Gy. In the range 0.5-2 Gy the enhancement of the radiation-induced synthesis of Hsp70 reached 60%. Our experimental results characterize changes in the Hsp70 synthesis after gamma irradiation as a part of the early cellular stress response in lymphocytes. (authors)

First evidence of pyrrolizidine alkaloid N-oxide-induced hepatic sinusoidal obstruction syndrome in humans.

Science.gov (United States)

Yang, Mengbi; Ruan, Jianqing; Gao, Hong; Li, Na; Ma, Jiang; Xue, Junyi; Ye, Yang; Fu, Peter Pi-Cheng; Wang, Jiyao; Lin, Ge

2017-12-01

Pyrrolizidine alkaloids (PAs) are among the most potent phytotoxins widely distributed in plant species around the world. PA is one of the major causes responsible for the development of hepatic sinusoidal obstruction syndrome (HSOS) and exerts hepatotoxicity via metabolic activation to form the reactive metabolites, which bind with cellular proteins to generate pyrrole-protein adducts, leading to hepatotoxicity. PA N-oxides coexist with their corresponding PAs in plants with varied quantities, sometimes even higher than that of PAs, but the toxicity of PA N-oxides remains unclear. The current study unequivocally identified PA N-oxides as the sole or predominant form of PAs in 18 Gynura segetum herbal samples ingested by patients with liver damage. For the first time, PA N-oxides were recorded to induce HSOS in human. PA N-oxide-induced hepatotoxicity was further confirmed on mice orally dosed of herbal extract containing 170 μmol PA N-oxides/kg/day, with its hepatotoxicity similar to but potency much lower than the corresponding PAs. Furthermore, toxicokinetic study after a single oral dose of senecionine N-oxide (55 μmol/kg) on rats revealed the toxic mechanism that PA N-oxides induced hepatotoxicity via their biotransformation to the corresponding PAs followed by the metabolic activation to form pyrrole-protein adducts. The remarkable differences in toxicokinetic profiles of PAs and PA N-oxides were found and attributed to their significantly different hepatotoxic potency. The findings of PA N-oxide-induced hepatotoxicity in humans and rodents suggested that the contents of both PAs and PA N-oxides present in herbs and foods should be regulated and controlled in use.

Procedimiento para diseñar el muestreo eólico en una región promisoria. Parte II.Implementación y aplicación; Procedure to design sampling of the wind speed in a promissory region. Part II. Implementation and application

Directory of Open Access Journals (Sweden)

Eduardo Terrero Matos

2015-06-01

Full Text Available En la Parte I de este artículo fue establecido el algoritmo general de un procedimiento para el diseño del muestreo de la velocidad del viento cuyos resultados tengan la capacidad de minimizar el error probable medio durante una estimación del comportamiento espacio-temporal de la velocidad del viento. En la Parte II se describe el algoritmo de selección de puntos de muestreo y el algoritmo para el cálculo del error probable de estimación. El procedimiento para diseñarlas redes de muestreo eólico es implementado en una aplicación informática que facilita la aplicación del procedimiento a la selección de los puntos donde se ubicarán las torres anemométricas en una región promisoria del municipio Moa en la Provincia Holguín, Cuba. Los resultados obtenidos son comparados con el diseño obtenido en el año 2007 por la Empresa de Ingeniería y Proyectos de Electricidad del Ministerio de Energía y Minas de la República de Cuba.In Part I of this article was established the general algorithmof a procedure for the sampling design of the wind speed and the results have the ability to minimize the average probable error for an estimate of the conduct spatiotemporal wind speed. In Part II the selection algorithm of sampling points and the algorithm for calculating the probable error estimation is described. The procedure for the samplingdesign is implemented in an computer software that facilitates the application from the procedure to the selection of the points where theanemometer towers will be located in a promissory region of the municipality Moa in the province Holguín, Cuba. The results are compared with the design obtained in 2007 by the Empresa de Ingeniería y Proyectos de Electricidad of the Ministry of Energy and Mines of the Republic of Cuba.

Alleviation of process-induced cracking of the antireflection TiN coating (ARC-TiN) in Al-Cu and Al-Cu-Si films

CERN Document Server

Peng, Y C; Yang, Y R; Hsieh, W Y; Hsieh, Y F

1999-01-01

The alleviation of cracking of the TiN-ARC layer on Al-Cu and Al-Cu-Si films after the development process has been achieved. For the TiN-ARC/Al-Cu system, the stress-induced defects decreased with increasing TiN-ARC layer thickness. In contrast, for the TiN-ARC/Al-Cu-Si system, Si nodules formed during cooling, thereby inducing poor coverage with high aspect-ratio holes. As a result, the photoresist developer penetrated through the films. Chemical vapor deposition of TiN-ARC or predeposition of a Ti Interposing layer was used to eliminate the formation of Si nodules.

Bosón de Higgs o la partícula de Dios: Entre el hito investigador y la quimera

OpenAIRE

Sanz Pascual, Julián

2013-01-01

Últimamente ha habido una eclosión informativa respecto a un descubrimiento científico que se supone va a ser histórico, la detección en el acelerador de partículas LHC de la partícula denominada el bosón de Higgs, bautizada como la partícula de Dios. Cabe considerar que la detección de esta partícula puede suponer una clave que va a revolucionar la física. Nosotros, que no somos físicos especializados, sino que pertenecemos a la filosofía, vamos a intentar una visión del tema desde ...

Acute toxicity induced by 2-aryl-N-methylsuccinimides.

Science.gov (United States)

Rankin, G O; Shih, H C; Teets, V J; Nicoll, D W; Brown, P I

1990-04-01

Phensuximide (PSX) is a 2-arylsuccinimide useful in the treatment of absence seizures. PSX is a mild urotoxicant and is structurally related to N-phenylsuccinimide (NPS) and its antifungal derivatives. Since substitution of the phenyl ring of NPS with chloro or tert-butyl groups can produce compounds with enhanced nephrotoxic potential, it was felt that similar substitutions on the phenyl ring of PSX also might produce derivatives with enhanced nephrotoxic potential. Three derivatives of PSX were prepared and tested: 2-(3-chlorophenyl)-N-methylsuccinimide (CPMS); 2-(4-tert-butylphenyl)-N-methylsuccinimide (BPMS) and 2-(3,5-dichlorophenyl)-N-methylsuccinimide (DPMS). In one set of experiments, male Fischer 344 rats were administered a single intraperitoneal (i.p.) injection of a succinimide (0.4 or 1.0 mmol kg-1) or vehicle (sesame oil, 2.5 ml kg-1) and renal function monitored at 24 and 48 h. Only minor changes in renal function were noted with the PSX derivatives. BPMS and DPMS (1.0 mmol kg-1) treatment induced mild renal tubular necrosis and thickening of the glomerular membranes. However, no significant morphological changes were noted in ureters, bladder or liver in any treatment group. In a second set of experiments, rats were pretreated with phenobarbital (75 mg kg-1 day-1, i.p., 3 days) followed by a single i.p. injection of DPMS (0.4 or 1.0 mmol kg-1) or DPMS vehicle. Renal function was monitored as before. Phenobarbital pretreatment did not markedly enhance the functional nephrotoxicity induced by DPMS (0.4 mmol), but tubular necrosis was greater than observed in non-phenobarbital-pretreated rats receiving DPMS (1.0 mmol kg-1). In addition, hepatotoxicity was observed as the appearance of numerous non-staining vacuoles in hypertrophied hepatocytes. In the phenobarbital plus DPMS (1.0 mmol kg-1) treatment group, all rats died by 48 h. Prior to death, rats exhibited increased proteinuria (+3), hematuria (+3) and blood urea nitrogen concentration. At 24 h

Programa para mejorar la atención en Mesas de Partes de la Corte Suprema de Justici

OpenAIRE

Pinto Malache, Rita Giovanna

2016-01-01

La presente investigación tuvo como objetivo general explicar el efecto del programa de capacitación en la atención que brindan las Mesas de Partes al usuario externo de la Corte Suprema de Justicia de la República del Perú. Año 2015; la población infinita, la muestra probabilística consideró 384 usuarios, en los cuales se ha empleado las variables: Programa de atención en mesa de partes y Atención al usuario. El método empleado en la investigación fue el hipotético deductivo,...

Análisis de los efectos de la inyección de agua en un filtro de partículas diesel sobre la acumulación de hollín

OpenAIRE

MARTÍNEZ GIL, JESÚS

2016-01-01

[ES] La instalación del filtro de partículas en la línea de escape de un motor Diésel provoca un aumento de la contrapresión de escape, viéndose incrementada a medida que crece la acumulación de partículas. Este fenómeno implica un aumento del consumo específico del motor, así como de las emisiones de CO2. Se ha descubierto que la inyección de agua a presión a la entrada del filtro disminuye la contrapresión generada por el mismo. En este proyecto se propone el estudio del proceso de la inyec...

ER stress inducer tunicamycin suppresses the self-renewal of glioma-initiating cell partly through inhibiting Sox2 translation.

Science.gov (United States)

Xing, Yang; Ge, Yuqing; Liu, Chanjuan; Zhang, Xiaobiao; Jiang, Jianhai; Wei, Yuanyan

2016-06-14

Glioma-initiating cells possess tumor-initiating potential and are relatively resistant to conventional chemotherapy and irradiation. Therefore, their elimination is an essential factor for the development of efficient therapy. Here, we report that endoplasmic reticulum (ER) stress inducer tunicamycin inhibits glioma-initiating cell self-renewal as determined by neurosphere formation assay. Moreover, tunicamycin decreases the efficiency of glioma-initiating cell to initiate tumor formation. Although tunicamycin induces glioma-initiating cell apoptosis, apoptosis inhibitor z-VAD-fmk only partly abrogates the reduction in glioma-initiating cell self-renewal induced by tunicamycin. Indeed, tunicamycin reduces the expression of self-renewal regulator Sox2 at translation level. Overexpression of Sox2 obviously abrogates the reduction in glioma-initiating cell self-renewal induced by tunicamycin. Taken together, tunicamycin suppresses the self-renewal and tumorigenic potential of glioma-initiating cell partly through reducing Sox2 translation. This finding provides a cue to potential effective treatment of glioblastoma through controlling stem cells.

LA PROBLEMÁTICA DE LAS PARTES Y EL CONTENIDO DE LA LEGITIMACIÓN ACTIVA EN LA CUESTIÓN DE INAPLICABILIDAD POR INCONSTITUCIONALIDAD DE LA LEY

OpenAIRE

Pica Flores, Rodrigo

2010-01-01

El presente trabajo aborda la justificación y el contenido de la legitimación activa en el proceso de inaplicabilidad por inconstitucionalidad de la ley en Chile, en una perspectiva de contexto de un sistema concentrado y concreto, para llegar posteriormente a la diferenciación entre la iniciativa de parte y la que corresponde a juez que conoce del proceso a quo. Se busca justificar la legitimación del juez de la causa, alternativa con la de las partes, pasando por la identificación y conteni...

Protective Roles of N-acetyl Cysteine and/or Taurine against Sumatriptan-Induced Hepatotoxicity

Directory of Open Access Journals (Sweden)

Javad Khalili Fard

2016-12-01

Full Text Available Purpose: Triptans are the drug category mostly prescribed for abortive treatment of migraine. Most recent cases of liver toxicity induced by triptans have been described, but the mechanisms of liver toxicity of these medications have not been clear. Methods: In the present study, we obtained LC50 using dose-response curve and investigated cell viability, free radical generation, lipid peroxide production, mitochondrial injury, lysosomal membrane damage and the cellular glutathione level as toxicity markers as well as the beneficial effects of taurine and/or N-acetyl cysteine in the sumatriptan-treated rat parenchymal hepatocytes using accelerated method of cytotoxicity mechanism screening. Results: It was revealed that liver toxicity induced by sumatriptan in in freshly isolated parenchymal hepatocytes is dose-dependent. Sumatriptan caused significant free radical generation followed by lipid peroxide formation, mitochondrial injury as well as lysosomal damage. Moreover, sumatriptan reduced cellular glutathione content. Taurine and N-acetyl cysteine were able to protect hepatocytes against sumatriptan-induced harmful effects. Conclusion: It is concluded that sumatriptan causes oxidative stress in hepatocytes and the decreased hepatocytes glutathione has a key role in the sumatriptan-induced harmful effects. Also, N-acetyl cysteine and/or taurine could be used as treatments in sumatriptan-induced side effects.

10 CFR Appendix N to Part 110 - Illustrative List of Lithium Isotope Separation Facilities, Plants and Equipment Under NRC's...

Science.gov (United States)

2010-01-01

..., Plants and Equipment Under NRC's Export Licensing Authority N Appendix N to Part 110 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) EXPORT AND IMPORT OF NUCLEAR EQUIPMENT AND MATERIAL Pt. 110, App. N Appendix N to Part 110—Illustrative List of Lithium Isotope Separation Facilities, Plants and Equipment...

Historia: pedagogía, psicología y educación (I parte

Directory of Open Access Journals (Sweden)

Carlos Alberto Santos M.

1991-05-01

Full Text Available RESUMEN En la primera parte de este ensayo, se presenta una visión  histórica del desarrollo en relación con la pedagogía, psicología y educación y su influencia en la acción y en la organización de los procesos educativos. Es a partir de la concepción que se tenga del hombre, de la sociedad y del mundo en general que se constituyen los sistemas educativos. Son diferentes los enfoques filosóficos y epistemológicos que han orientado a la sociedad histórica, en su pensamiento y acción educativa

Una hipótesis de trabajo para investigar el progreso en la comprensión de la alimentación humana por parte de los alumnos

OpenAIRE

Cabello Garrido, A.

2009-01-01

Esta comunicación forma parte de un trabajo más amplio encaminado a estudiar el progreso en la comprensión de la alimentación humana por parte de los alumnos. Se encuadra en la línea de investigación sobre el progreso en la comprensión de dominios específicos desde las perspectivas de las teorías de los alumnos. Se presenta la elaboración del mapa del dominio sobre la alimentación humana, como hipótesis de trabajo. Para ello, se describen las dimensiones que se consideran importantes para la ...

Evolución de la distribución de tensiones en un cuerpo cerámico durante la cocción. Parte 2: Cálculo de los perfiles

Directory of Open Access Journals (Sweden)

Camacho, H.

2003-12-01

Full Text Available Stress distribution during firing is reported. The calculation is performed based on the model stated in the part 1. Starting data correspond to the constitutive models presented in part 1. Besides, an experimental measurement was performed to obtain the Young modulus and the thermal dilatation to be considered for calculations. Starting from the stress equilibrium, it may be reported that: 1 The stress distribution during hot forging is always similar in spite of different pressing conditions and different considered constitutive behaviors. 2 The thermo-elastic behavior may be considered as an acceptable approximation. 3 The temperature gradients and their effect on the body viscosity and on thermal dilatation play an essential role in the stress distribution.

Se reporta la distribución de las tensiones durante la cocción. El cálculo de las mismas se efectúa a través del modelo planteado en la primera parte. Los datos de partida corresponden a los modelos constitutivos presentados en la primera parte. Además, se realizó una medición experimental del módulo de Young y de la dilatación térmica para ser tenida en cuenta en los cálculos. Tomando como base el equilibrio en tensiones se reporta que: 1 La distribución de tensiones en el prensado en caliente es semejante a pesar de condiciones diferentes de prensado y de considerar diferentes comportamientos constitutivos. 2 El comportamiento termo-elástico puede usarse como una aproximación aceptable para los materiales arcillosos. 3 Los gradientes de temperatura y su efecto en la viscosidad del cuerpo y en las dilataciones térmicas juegan un papel esencial en la distribución de tensiones.

Antibacterianos de acción sistémica: Parte I. Antibióticos betalactámicos

OpenAIRE

Manuel Cué Brugueras; Moisés Morejón García

1998-01-01

Se presenta una revisión bibliográfica sobre los antibacterianos de acción sistémica, de los cuales en esta primera parte se desarrolla la de los antibióticos betalactámicos, así como algunos conceptos básicos y los diferentes tipos de clasificación de los antibióticos en general. Se abordan los derivados penicilánicos y cafalosporánicos más conocidos internacionalmenteA literature review on systemic antibacterial drugs is presented. This first part includes beta-lactam antibiotics, some basi...

Effect of coated urea and non-coated urea on grain yield, N uptake and N distribution in different parts of maize

International Nuclear Information System (INIS)

Ren Yi; Li Guihua; Zhao Linping; Zhang Shuxiang

2011-01-01

In order to regulate nitrogen metabolism with nitrogen application rate and to increase nitrogen use efficiency, an isotopic method was used to compare grain yield, biomass and nitrogen use efficiency of coated urea (CU) to those of non-coated urea (U) at the N application rates of 0, 100, 150 and 225 kg/hm 2 . Results showed that CU significantly increased maize N uptake from 15 N fertilizer and aboveground biomass. The nitrogen use efficiency ( 15 NUE) of CU was 13.3-21.4% greater than that of U. There was a significant different of fertilizer 15 N uptake between CU and U in maize parts. And N uptake of CU treatment followed the order of seed > leaves > straws > cob > husk, while N uptake of U treatment was in the order of seed > straws > leaves > cob > husk. The N uptake of maize parts by both CU and U followed the same order when non-isotopic method was applied. No significant variations were observed among treatments in N uptake, Nitrogen Harvest Index and grain yield. The reason maybe that low soil temperatures (< 10 ℃) from the fourth week of October to next April reduced N uptake of winter wheat, therefore, residual NO3-N in cultivated soil layer was high after harvest. Thus, maize N uptake was more dependent on the shoot growth potential than fertilizer amount and types under high amount of available nitrogen. (authors)

Relación céntrica: revisión de conceptos y técnicas para su registro. Parte II Centric relation: concepts revision and recording techniques. Part II

OpenAIRE

A. Orozco Varo; G. Arroyo Cruz; R. Martínez de Fuentes; J. Ventura de la Torre; D. Cañadas Rodríguez; E. Jiménez Castellanos

2008-01-01

La relación céntrica ha sido objeto de disparidad de criterios en la odontología durante más de un siglo. A lo largo de este trabajo, vamos a exponer diferentes métodos usados tanto para obtener el registro, como para comprobar su certeza y corroborar la posición condilar. Dado que no existe evidencia científica en el tema, en este trabajo, revisaremos los estudios experimentales que aparecen en la literatura. Los hemos divididos en dos partes, la primera relacionada con la definición de rela...

Relación céntrica: revisión de conceptos y técnicas para su registro. Parte I Centric relation: concepts revision and recording techniques. Part I

OpenAIRE

A. Orozco Varo; G. Arroyo Cruz; R. Martínez de Fuentes; J. Ventura de la Torre; D. Cañadas Rodríguez; E. Jiménez Castellanos

2008-01-01

La relación céntrica ha sido objeto de disparidad de criterios en la odontología durante más de un siglo. A lo largo de este trabajo, vamos a exponer diferentes métodos usados tanto para obtener el registro, como para comprobar su certeza y corroborar la posición condilar. Dado que no existe evidencia científica en el tema, en este trabajo, revisaremos los estudios experimentales que aparecen en la literatura. Los hemos divididos en dos partes, la primera relacionada con la definición de rela...

Mitochondrial N-formyl peptides induce cardiovascular collapse and sepsis-like syndrome

Science.gov (United States)

McCarthy, Cameron G.; Szasz, Theodora; Goulopoulou, Styliani; Webb, R. Clinton

2015-01-01

Fifty percent of trauma patients who present sepsis-like syndrome do not have bacterial infections. This condition is known as systemic inflammatory response syndrome (SIRS). A unifying factor of SIRS and sepsis is cardiovascular collapse. Trauma and severe blood loss cause the release of endogenous molecules known as damage-associated molecular patterns. Mitochondrial N-formyl peptides (F-MIT) are damage-associated molecular patterns that share similarities with bacterial N-formylated peptides and are potent immune system activators. The goal of this study was to investigate whether F-MIT trigger SIRS, including hypotension and vascular collapse via formyl peptide receptor (FPR) activation. We evaluated cardiovascular parameters in Wistar rats treated with FPR or histamine receptor antagonists and inhibitors of the nitric oxide pathway before and after F-MIT infusion. F-MIT, but not nonformylated peptides or mitochondrial DNA, induced severe hypotension via FPR activation and nitric oxide and histamine release. Moreover, F-MIT infusion induced hyperthermia, blood clotting, and increased vascular permeability. To evaluate the role of leukocytes in F-MIT-induced hypotension, neutrophil, basophil, or mast cells were depleted. Depletion of basophils, but not neutrophils or mast cells, abolished F-MIT-induced hypotension. Rats that underwent hemorrhagic shock increased plasma levels of mitochondrial formylated proteins associated with lung damage and antagonism of FPR ameliorated hemorrhagic shock-induced lung injury. Finally, F-MIT induced vasodilatation in isolated resistance arteries via FPR activation; however, F-MIT impaired endothelium-dependent relaxation in the presence of blood. These data suggest that F-MIT may be the link among trauma, SIRS, and cardiovascular collapse. PMID:25637548

Interfacial Exchange Coupling Induced Anomalous Anisotropic Magnetoresistance in Epitaxial γ′-Fe 4 N/CoN Bilayers

KAUST Repository

Li, Zirun; Mi, Wenbo; Wang, Xiaocha; Zhang, Xixiang

2015-01-01

Anisotropic magnetoresistance (AMR) of the facing-target reactively sputtered epitaxial γ′-Fe4N/CoN bilayers is investigated. The phase shift and rectangular-like AMR appears at low temperatures, which can be ascribed to the interfacial exchange coupling. The phase shift comes from the exchange bias (EB) that makes the magnetization lag behind a small field. When the γ′-Fe4N thickness increases, the rectangular-like AMR appears. The rectangular-like AMR should be from the combined contributions including the EB-induced unidirectional anisotropy, intrinsic AMR of γ′-Fe4N layer and interfacial spin scattering.

Interfacial Exchange Coupling Induced Anomalous Anisotropic Magnetoresistance in Epitaxial γ′-Fe 4 N/CoN Bilayers

KAUST Repository

Li, Zirun

2015-02-02

Anisotropic magnetoresistance (AMR) of the facing-target reactively sputtered epitaxial γ′-Fe4N/CoN bilayers is investigated. The phase shift and rectangular-like AMR appears at low temperatures, which can be ascribed to the interfacial exchange coupling. The phase shift comes from the exchange bias (EB) that makes the magnetization lag behind a small field. When the γ′-Fe4N thickness increases, the rectangular-like AMR appears. The rectangular-like AMR should be from the combined contributions including the EB-induced unidirectional anisotropy, intrinsic AMR of γ′-Fe4N layer and interfacial spin scattering.

Riccardin D-N induces lysosomal membrane permeabilization by inhibiting acid sphingomyelinase and interfering with sphingomyelin metabolism in vivo

Energy Technology Data Exchange (ETDEWEB)

Li, Lin [Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012 (China); Niu, Huanmin [Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan 250012 (China); Sun, Bin [Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012 (China); Xiao, Yanan [School of Pharmaceutical Science, Shandong University, Jinan 250012 (China); Li, Wei [Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012 (China); Yuan, Huiqing [Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan 250012 (China); Lou, Hongxiang, E-mail: louhongxiang@sdu.edu.cn [Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012 (China)

2016-11-01

Lysosomes are important targets for anticancer drug discovery. Our previous study showed that Riccardin D-N (RD-N), a natural macrocylic bisbibenzyl derivative produced by Mannich reaction, induced cell death by accumulating in lysosomes. Experiments were performed on human lung squamous cell carcinoma tissue from left inferior lobar bronchus of patient xenografts and H460 cells. RD-N was administrated for 25 days. The specimens of xenografts in Balb/c athymic (nu +/nu +) male mice were removed for immunohistochemistry, subcellular fractionation, enzyme activities and Western blotting analysis. mRFP-GFP-LC3 reporter was used to examine autophagy in H460 cells. Sphingomyelin assay was evaluated by thin-layer chromatography and assay kit. Lysosomal membrane permeabilization (LMP) caused by acid sphingomyelinase (ASM) inhibition and subsequent changes of sphingomyelin (SM) metabolism selectively destabilized the cancer cell lysosomes in RD-N-treated H460 cells in vitro and tumor xenograft model in vivo. The destabilized lysosomes induced the release of cathepsins from the lysosomes into the cytosol and further triggered cell death. These results explain the underlying mechanism of RD-N induced LMP. It can be concluded that a more lysosomotropic derivative was synthesized by introduction of an amine group, which could have more potential applications in cancer therapy. - Highlights: • Riccardin D-N (RD-N) significantly downregulated LAMP1 expressions. • RD-N inhibited the acid sphingomyelinase activity. • RD-N induced lysosomal membrane permeabilization in vivo. • RD-N induced SM accumulation in the lysosomal membranes. • RD-N also induced the release of cathepsins from destabilized lysosomes.

Riccardin D-N induces lysosomal membrane permeabilization by inhibiting acid sphingomyelinase and interfering with sphingomyelin metabolism in vivo

International Nuclear Information System (INIS)

Li, Lin; Niu, Huanmin; Sun, Bin; Xiao, Yanan; Li, Wei; Yuan, Huiqing; Lou, Hongxiang

2016-01-01

Lysosomes are important targets for anticancer drug discovery. Our previous study showed that Riccardin D-N (RD-N), a natural macrocylic bisbibenzyl derivative produced by Mannich reaction, induced cell death by accumulating in lysosomes. Experiments were performed on human lung squamous cell carcinoma tissue from left inferior lobar bronchus of patient xenografts and H460 cells. RD-N was administrated for 25 days. The specimens of xenografts in Balb/c athymic (nu +/nu +) male mice were removed for immunohistochemistry, subcellular fractionation, enzyme activities and Western blotting analysis. mRFP-GFP-LC3 reporter was used to examine autophagy in H460 cells. Sphingomyelin assay was evaluated by thin-layer chromatography and assay kit. Lysosomal membrane permeabilization (LMP) caused by acid sphingomyelinase (ASM) inhibition and subsequent changes of sphingomyelin (SM) metabolism selectively destabilized the cancer cell lysosomes in RD-N-treated H460 cells in vitro and tumor xenograft model in vivo. The destabilized lysosomes induced the release of cathepsins from the lysosomes into the cytosol and further triggered cell death. These results explain the underlying mechanism of RD-N induced LMP. It can be concluded that a more lysosomotropic derivative was synthesized by introduction of an amine group, which could have more potential applications in cancer therapy. - Highlights: • Riccardin D-N (RD-N) significantly downregulated LAMP1 expressions. • RD-N inhibited the acid sphingomyelinase activity. • RD-N induced lysosomal membrane permeabilization in vivo. • RD-N induced SM accumulation in the lysosomal membranes. • RD-N also induced the release of cathepsins from destabilized lysosomes.

Expansión de los suelos arcillosos parcialmente saturados. Segunda parte

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Lisandro Berltrán Moreno

1995-07-01

Full Text Available En la segunda parte del artículo se hará una breve descripción de los factores que influyen sobre la expansividad de los suelos arcillosos, y se indicaran las soluciones más adecuadas para evitar los problemas causados por la expansión de los suelos arcillosos, cuando sobre ellos se construyen estructuras livianas. EI artículo fue presentado en el Primer Encuentro Nacional de Ingenieros de Suelos y de Estructuras, evento que se realizó en Santafé de Bogotá entre el4 y el 6 de Septiembre de 1991.

Dependence of InGaN solar cell performance on polarization-induced electric field and carrier lifetime

International Nuclear Information System (INIS)

Yang Jing; Zhao De-Gang; Jiang De-Sheng; Liu Zong-Shun; Chen Ping; Li Liang; Wu Liang-Liang; Le Ling-Cong; Li Xiao-Jing; He Xiao-Guang; Yang Hui; Wang Hui; Zhu Jian-Jun; Zhang Shu-Ming; Zhang Bao-Shun

2013-01-01

The effects of Mg-induced net acceptor doping concentration and carrier lifetime on the performance of a p—i—n InGaN solar cell are investigated. It is found that the electric field induced by spontaneous and piezoelectric polarization in the i-region could be totally shielded when the Mg-induced net acceptor doping concentration is sufficiently high. The polarization-induced potential barriers are reduced and the short circuit current density is remarkably increased from 0.21 mA/cm 2 to 0.95 mA/cm 2 by elevating the Mg doping concentration. The carrier lifetime determined by defect density of i-InGaN also plays an important role in determining the photovoltaic properties of solar cell. The short circuit current density severely degrades, and the performance of InGaN solar cell becomes more sensitive to the polarization when carrier lifetime is lower than the transit time. This study demonstrates that the crystal quality of InGaN absorption layer is one of the most important challenges in realizing high efficiency InGaN solar cells. (interdisciplinary physics and related areas of science and technology)

High-n helicity-induced shear Alfven eigenmodes

International Nuclear Information System (INIS)

Nakajima, N.; Cheng, C.Z.; Okamoto, M.

1992-05-01

The high-n Helicity-induced shear Alfven Eigenmodes (HAE) are considered both analytically and numerically for the straight helical magnetic system, where n is the toroidal mode number. The eigenmode equation for the high-n HAE modes is derived along the field line and with the aid of the averaging method is shown to reduce to the Mathieu equation asymptotically. The discrete HAE modes are shown to exist inside the continuum spectrum gaps. The continuous spectrum gaps appear around ω 2 = ω A 2 [N(lι-m)/2] 2 for N = 1,2,.., where ω A is the toroidal Alfven transit frequency, and l, m, and ι are the polarity of helical coils, the toroidal pitch number of helical coils, and the rotational transform, respectively. For the same ω A and ι, the frequency of the helical continuum gap is larger than that of the continuum gap in tokamak plasmas by |l-ι -1 m|. The polarity of helical coils l plays a crucial role in determining the spectrum gaps and the properties of the high-n HAE modes. The spectrum gaps near the magnetic axis are created by the helical ripple with circular flux surfaces for l = 1, and ≥ 3 helicals. For l = 2 helical systems, the spectrum gaps are created by the ellipticity of the flux surfaces. These analytical results for the continuum gaps and the existence of the high-n HAE modes in the continuum gaps are confirmed numerically for the l = 2 case, and we find that the HAE modes exist for mode structures with the even and the odd parities. (author)

Plastic Deformation Induced by Nanoindentation Test Applied on ZrN/Si3N4 Multilayer Coatings

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Zhengtao Wu

2017-12-01

Full Text Available ZrN/Si3N4 multilayer coating that alternates with either nanocrystalline ZrN or amorphous Si3N4 interlayers was fabricated by reactively magnetron sputtering in an Ar-N2 mixture atmosphere. The thicknesses of the nanocrystalline ZrN and the amorphous Si3N4 interlayers are ~12.5 and 2.5 nm, respectively. The ZrN/Si3N4 coating exhibits a promoted hardness of 28.6 ± 1.2 GPa when compared to the binary ZrN. Microstructure evolution just underneath the nanoindentation impression of the ZrN/Si3N4 multilayer coating has been investigated. The result indicates that both ZrN nanograin rotations and plastic flow of the Si3N4 interlayers contribute to the permanent deformation of the multilayer coating induced by the nanoindentation. In addition, the introduction of the a-Si3N4 interlayers hinders both the initiation and propagation of microcracks when the multilayer coating was applied to the scratch test. The propagation deflection of the microcracks was observed attributed to the heterogenous interface, which produces the hardness promotion of the multilayer coating eventually.

Estado actual del proceso de territorialización del espacio ultraterrestre por parte de Colombia y recomendaciones para su consolidación

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María Ximena Correa Olarte

2017-07-01

Full Text Available El objetivo de este artículo es evidenciar la carencia de un proceso consolidado de territorialización del espacio ultraterrestre por parte de Colombia y hacer recomendaciones a partir de la teoría de la geografía que permitan iniciar dicho proceso. El espacio ultraterrestre es aquella franja del espacio exterior en la que los satélites artificiales orbitan alrededor de la Tierra y es más lejana que el espacio aéreo de cada Estado. En dicho espacio, únicamente los Estados con desarrollo tecnológico y capacidad de inversión importante en áreas espaciales hacen uso de este, territorializándolo. En este artículo, se destaca la importancia de la concienciación sobre la utilización y ocupación de ese espacio, la promulgación de leyes y políticas bajo un marco jurídico colombiano consolidado y el desarrollo técnico-científico y académico para iniciar un proceso de territorialización del espacio ultraterrestre por parte de Colombia.

N-3 Polyunsaturated Fatty Acids Decrease the Protein Expression of Soluble Epoxide Hydrolase via Oxidative Stress-Induced P38 Kinase in Rat Endothelial Cells.

Science.gov (United States)

Okada, Takashi; Morino, Katsutaro; Nakagawa, Fumiyuki; Tawa, Masashi; Kondo, Keiko; Sekine, Osamu; Imamura, Takeshi; Okamura, Tomio; Ugi, Satoshi; Maegawa, Hiroshi

2017-06-24

N -3 polyunsaturated fatty acids (PUFAs) improve endothelial function. The arachidonic acid-derived metabolites (epoxyeicosatrienoic acids (EETs)) are part of the endothelial hyperpolarization factor and are vasodilators independent of nitric oxide. However, little is known regarding the regulation of EET concentration by docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in blood vessels. Sprague-Dawley rats were fed either a control or fish oil diet for 3 weeks. Compared with the control, the fish oil diet improved acetylcholine-induced vasodilation and reduced the protein expression of soluble epoxide hydrolase (sEH), a key EET metabolic enzyme, in aortic strips. Both DHA and EPA suppressed sEH protein expression in rat aorta endothelial cells (RAECs). Furthermore, the concentration of 4-hydroxy hexenal (4-HHE), a lipid peroxidation product of n -3 PUFAs, increased in n -3 PUFA-treated RAECs. In addition, 4-HHE treatment suppressed sEH expression in RAECs, suggesting that 4-HHE (derived from n -3 PUFAs) is involved in this phenomenon. The suppression of sEH was attenuated by the p38 kinase inhibitor (SB203580) and by treatment with the antioxidant N-acetyl-L-cysteine. In conclusion, sEH expression decreased after n -3 PUFAs treatment, potentially through oxidative stress and p38 kinase. Mild oxidative stress induced by n -3 PUFAs may contribute to their cardio-protective effect.

Intra-articular vs. systemic administration of etanercept in antigen-induced arthritis in the temporomandibular point. Part I: histological effects

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Nyengaard Jens R

2009-02-01

Full Text Available Abstract Background Temporomandibular joint (TMJ arthritis in children causes alterations in craniomandibular growth. This abnormal growth may be prevented by an early anti-inflammatory intervention. We have previously shown that intra-articular (IA corticosteroid reduces TMJ inflammation, but causes concurrent mandibular growth inhibition in young rabbits. Blockage of TNF-α has already proven its efficacy in children with juvenile idiopathic arthritis not responding to standard therapy. In this paper we evaluate the effect of IA etanercept compared to subcutaneous etanercept in antigen-induced TMJ-arthritis in rabbits on histological changes using histomorphometry and stereology. This article presents the data and discussion on the anti-inflammatory effects of systemic and IA etanercept. In Part II the data on the effects of systemic and IA etanercept on facial growth are presented. Methods Forty-two rabbits (10 weeks old pre-sensitized with ovalbumin and locally induced inflammation in the temporomandibular joints were divided into three groups: a placebo group receiving IA saline injections in both joints one week after arthritis induction (n = 14, an IA etanercept group receiving 0.1 mg/kg etanercept per joint one week after arthritis induction (n = 14 and a systemic etanercept group receiving 0.8 mg/kg etanercept weekly throughout the 12-week study (n = 14. Arthritis was maintained by giving four inductions three weeks apart. Additional IA saline or etanercept injections were also given one week after the re-inductions. Histomorphometric and unbiased stereological methods (optical fractionator were used to assess and estimate the inflammation in the joints. Results The histomorphometry showed synovial proliferation in all groups. The plasma cell count obtained by the optical fractionator was significantly reduced when treating with systemic etanercept but not with IA etanercept. Semi-quantitative assessments of synovial proliferation and

MULTIFUNCIONALIDAD, PARTES INTERESADAS Y LEGITIMIDAD SOCIAL DEL REGADÍO: APROXIMACIÓN A TRES CANALES SUR-EUROPEOS

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Sandra Ricart Casadevall

2015-01-01

Full Text Available La gestión del regadío es protagonista de un debate multifocal y supra escalar donde parte de la sociedad cuestiona los límites socioeconómicos y ambientales asociados a su práctica, poniendo el énfasis en su capital territorial y su capacidad de adaptación ante los retos venideros. En el ámbito sur-europeo la yuxtaposición de canales tradicionales, modernizados y de nueva creación explica buena parte del dinamismo protagonizado por la matriz rural. Los resultados obtenidos en tres casos de estudio de carácter multifuncional y marco sur-europeo (canal Segarra-Garrigues –Lérida–, canal de la Neste –Hautes-Pyrénées– y canal de la Muzza –Lombardia– enfatizan el debate sobre el futuro del regadío y apuesta por una gestión territorial del mismo.

Ameliorative Effects of Dimetylthiourea and N-Acetylcysteine on Nanoparticles Induced Cyto-Genotoxicity in Human Lung Cancer Cells-A549

Science.gov (United States)

Srivastava, Ritesh Kumar; Rahman, Qamar; Kashyap, Mahendra Pratap; Lohani, Mohtashim; Pant, Aditya Bhushan

2011-01-01

We study the ameliorative potential of dimetylthiourea (DMTU), an OH• radical trapper and N-acetylcysteine (NAC), a glutathione precursor/H2O2 scavenger against titanium dioxide nanoparticles (TiO2-NPs) and multi-walled carbon nanotubes (MWCNTs) induced cyto-genotoxicity in cultured human lung cancer cells-A549. Cytogenotoxicity was induced by exposing the cells to selected concentrations (10 and 50 µg/ml) of either of TiO2-NPs or MWCNTs for 24 h. Anti-cytogenotoxicity effects of DMTU and NAC were studied in two groups, i.e., treatment of 30 minutes prior to toxic insult (short term exposure), while the other group received DMTU and NAC treatment during nanoparticles exposure, i.e., 24 h (long term exposure). Investigations were carried out for cell viability, generation of reactive oxygen species (ROS), micronuclei (MN), and expression of markers of oxidative stress (HSP27, CYP2E1), genotoxicity (P53) and CYP2E1 dependent n- nitrosodimethylamine-demethylase (NDMA-d) activity. In general, the treatment of both DMTU and NAC was found to be effective significantly against TiO2-NPs and MWCNTs induced cytogenotoxicity in A549 cells. Long-term treatment of DMTU and NAC during toxic insults has shown better prevention than short-term pretreatment. Although, cells responded significantly to both DMTU and NAC, but responses were chemical specific. In part, TiO2-NPs induced toxic responses were mediated through OH• radicals generation and reduction in the antioxidant defense system. While in the case of MWCNTs, adverse effects were primarily due to altering/hampering the enzymatic antioxidant system. Data indicate the applicability of human lung cancer cells-A549 as a pre-screening tool to identify the target specific prophylactic and therapeutic potential of drugs candidate molecules against nanoparticles induced cellular damages. PMID:21980536

Ameliorative effects of dimetylthiourea and N-acetylcysteine on nanoparticles induced cyto-genotoxicity in human lung cancer cells-A549.

Directory of Open Access Journals (Sweden)

Ritesh Kumar Srivastava

Full Text Available We study the ameliorative potential of dimetylthiourea (DMTU, an OH• radical trapper and N-acetylcysteine (NAC, a glutathione precursor/H₂O₂ scavenger against titanium dioxide nanoparticles (TiO₂-NPs and multi-walled carbon nanotubes (MWCNTs induced cyto-genotoxicity in cultured human lung cancer cells-A549. Cytogenotoxicity was induced by exposing the cells to selected concentrations (10 and 50 µg/ml of either of TiO₂-NPs or MWCNTs for 24 h. Anti-cytogenotoxicity effects of DMTU and NAC were studied in two groups, i.e., treatment of 30 minutes prior to toxic insult (short term exposure, while the other group received DMTU and NAC treatment during nanoparticles exposure, i.e., 24 h (long term exposure. Investigations were carried out for cell viability, generation of reactive oxygen species (ROS, micronuclei (MN, and expression of markers of oxidative stress (HSP27, CYP2E1, genotoxicity (P⁵³ and CYP2E1 dependent n- nitrosodimethylamine-demethylase (NDMA-d activity. In general, the treatment of both DMTU and NAC was found to be effective significantly against TiO₂-NPs and MWCNTs induced cytogenotoxicity in A549 cells. Long-term treatment of DMTU and NAC during toxic insults has shown better prevention than short-term pretreatment. Although, cells responded significantly to both DMTU and NAC, but responses were chemical specific. In part, TiO₂-NPs induced toxic responses were mediated through OH• radicals generation and reduction in the antioxidant defense system. While in the case of MWCNTs, adverse effects were primarily due to altering/hampering the enzymatic antioxidant system. Data indicate the applicability of human lung cancer cells-A549 as a pre-screening tool to identify the target specific prophylactic and therapeutic potential of drugs candidate molecules against nanoparticles induced cellular damages.

Factores de riesgo de preeclampsia: enfoque inmunoendocrino. Parte I Risk factors for preeclampsia: an immunoendocrine approach. Part I

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Jeddú Cruz Hernández

2007-12-01

Full Text Available En esta primera parte se realiza una amplia revisión de los factores clásicos de riesgo de preeclampsia, enfatizando en los aspectos inmunoendocrinos en cada uno de los casos. Se propuso una clasificación que los divide en 2 grandes grupos: maternos y ambientales, y esta constituye el eje central a partir del cual se realiza la discusión de los diferentes aspectos que integran esta revisión, la cual evidencia la importancia que tienen el sistema inmunológico y el endocrino en la fisiopatología, y el surgimiento de la enfermedad hipertensiva inducida por el embarazo.In this first part, a wide review of the classical risk factors for preeclampsia was made, making emphasis on the endocrine aspects in each case. It was proposed a classification that divided them into 2 large groups: maternal and environmental. This was the central axis from which the different aspects of this review were discussed, evidencing the importance of the immunological and endocrine systems in the physiopathology, and the appearance of the hypertensive disease induced by pregnancy.

Temperature-induced phase transition in hydrogels of interpenetrating networks poly(N-isopropylmethacrylamide)/poly(N-isopropylacrylamide)

Czech Academy of Sciences Publication Activity Database

Šťastná, J.; Hanyková, L.; Sedláková, Zdeňka; Valentová, H.; Spěváček, Jiří

2013-01-01

Roč. 291, č. 10 (2013), s. 2409-2417 ISSN 0303-402X R&D Projects: GA ČR GA202/09/1281 Institutional support: RVO:61389013 Keywords : temperature-induced volume phase transition * poly (N-isopropylmethacrylamide) poly (Nisopropylacrylamide) interpenetrating network * 1H NMR spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.410, year: 2013

P-n junction diodes with polarization induced p-type graded InxGa1-xN layer

Science.gov (United States)

Enatsu, Yuuki; Gupta, Chirag; Keller, Stacia; Nakamura, Shuji; Mishra, Umesh K.

2017-10-01

In this study, p-n junction diodes with polarization induced p-type layer are demonstrated on Ga polar (0001) bulk GaN substrates. A quasi-p-type region is obtained by linearly grading the indium composition in un-doped InxGa1-xN layers from 0% to 5%, taking advantage of the piezoelectric and spontaneous polarization fields which exist in group III-nitride heterostructures grown in the typical (0001) or c-direction. The un-doped graded InxGa1-xN layers needed to be capped with a thin Mg-doped InxGa1-xN layer to make good ohmic contacts and to reduce the on-resistance of the p-n diodes. The Pol-p-n junction diodes exhibited similar characteristics compared to reference samples with traditional p-GaN:Mg layers. A rise in breakdown voltage from 30 to 110 V was observed when the thickness of the graded InGaN layer was increased from 100 to 600 nm at the same grade composition.

Registros de representación semiótica del concepto de función exponencial. Parte I

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María G. Castro Rodríguez

2017-01-01

Full Text Available El concepto de función es un objeto matemático fundamental en el proceso de abstracción, en particular, en la función exponencial, la cual es preponderante para el aprendizaje de varios procesos físicos y sociales. Esta función, es parte de los programas de matemáticas desde elinicio de la instrucción escolar hasta el nivel superior, donde la extensión de los mismos, ha limitadosu tiempo de estudio.Aunado a este problema, el sistema tradicional de enseñanza sólo incluye algunos cambios de representación, que de acuerdo con La teoría de registros de representación semiótica (Duval, 1993 no son suficientes para que el estudiante adquiera un entendimiento significativo de esta función. En este artículo se muestra el efecto de la instrucción recibida mediante el coeficiente ganancia normalizada de Hake (1998 a través de una secuencia didáctica. Esta secuencia se fundamenta en los diversos cambios de registros de representación semiótica del concepto de función. Se muestran los efectos de entendimiento de dos grupos, el experimental y el de control. Los resultados indican que el grupo experimental obtuvo una mayor ganancia, y accedió a niveles de entendimiento de Hitt (1998 más altos en comparación con el grupo de control. Además, se obtuvo una correlación de 0.5 entre estos dos índices.

Effects of X-irradiation on N-methyl-N-nitrosourea-induced multi-organ carcinogenesis in rats

International Nuclear Information System (INIS)

Morishita, Yukiko; Tanaka, Takuji; Mori, Hideki; Sasaki, Shunsaku.

1993-01-01

The effects of X-irradiation on N-methyl-N-nitrosourea (MNU)-induced multi-organ carcinogenesis were examined in both sexes of ACI/N rats. At 6 weeks of age, rats in groups 1 (25 males, 25 females) and 3 (24 males, 23 females) received a single intraperitoneal injection of MNU (25 mg/kg body weight), while those in groups 2 (25 males, 26 females) and 4 (25 males, 25 females) were administered the carcinogen at a dose of 50 mg/kg body weight. At 10 weeks of age, group 3 and group 4 were X-irradiated at dose of 3 Gy. Group 5 (24 males, 24 females) received X-irradiation alone. Group 6 (21 males, 21 females) served as an untreated control. As a result, neoplasms developed mainly in the digestive tract, kidney, uterus, and hematopoietic organ in groups 1-5. The incidences of adenocarcinoma in small and large intestines of male rats of group 4 (50 mg/kg MNU and X-irradiation) (small intestine: 48%, large intestine: 32%) were significantly higher than those of group 2 (50 mg/kg MNU) (small intestine: 17%, p<0.05; large intestine: 8%, p<0.05), and also the frequency of adenocarcinoma in the large intestine of males of group 3 (25 mg/kg MNU and X-irradiation) (22%) was significantly greater than that of group 1 (25 mg/kg MNU) (0%, p<0.05). These results indicated that X-irradiation enhanced the development of intestinal neoplasms induced by MNU in male ACI/N rats. (author)

Effects of X-irradiation on N-methyl-N-nitrosourea-induced multi-organ carcinogenesis in rats

Energy Technology Data Exchange (ETDEWEB)

Morishita, Yukiko; Tanaka, Takuji; Mori, Hideki (Gifu Univ. (Japan). Faculty of Medicine); Sasaki, Shunsaku

1993-01-01

The effects of X-irradiation on N-methyl-N-nitrosourea (MNU)-induced multi-organ carcinogenesis were examined in both sexes of ACI/N rats. At 6 weeks of age, rats in groups 1 (25 males, 25 females) and 3 (24 males, 23 females) received a single intraperitoneal injection of MNU (25 mg/kg body weight), while those in groups 2 (25 males, 26 females) and 4 (25 males, 25 females) were administered the carcinogen at a dose of 50 mg/kg body weight. At 10 weeks of age, group 3 and group 4 were X-irradiated at dose of 3 Gy. Group 5 (24 males, 24 females) received X-irradiation alone. Group 6 (21 males, 21 females) served as an untreated control. As a result, neoplasms developed mainly in the digestive tract, kidney, uterus, and hematopoietic organ in groups 1-5. The incidences of adenocarcinoma in small and large intestines of male rats of group 4 (50 mg/kg MNU and X-irradiation) (small intestine: 48%, large intestine: 32%) were significantly higher than those of group 2 (50 mg/kg MNU) (small intestine: 17%, p<0.05; large intestine: 8%, p<0.05), and also the frequency of adenocarcinoma in the large intestine of males of group 3 (25 mg/kg MNU and X-irradiation) (22%) was significantly greater than that of group 1 (25 mg/kg MNU) (0%, p<0.05). These results indicated that X-irradiation enhanced the development of intestinal neoplasms induced by MNU in male ACI/N rats. (author).

Fabricación y caracterización de materiales Ag-Cd/CdO producidos mediante incorporación de partículas de CdO en aleaciones Ag-Cd líquidas

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Equihua-Guillén, Fabián

2014-03-01

Full Text Available In the present work it has been investigated the kinetic behavior of internal oxidation processes of strips of Ag-Cd/CdO materials fabricated by adding CdO particles (size of 5 and 20 μm in liquid Ag-Cd alloys. It has been established the metallurgical mechanism that controls the formation of the thickness covered with CdO particles produced by internal oxidation of the Ag-Cd/CdO material. It has been developed, successfully, a metallographic preparation technique for characterizing the morphology, size and distribution of CdO particles produced by heat treatment of internal oxidation on the surface of each sample based on the distance from the original surface to the boundary of dispersed CdO particles. The material strips were sequentially roughed on its surface and the roughing thickness was measured in the cross section of each new surface to determine the number of particles per area and average particle size.En el presente trabajo se investigó el comportamiento cinético del proceso de oxidación interna de láminas del material Ag-Cd/CdO fabricado mediante adición de partículas de CdO con tamaño de 5 y 20 μm en aleaciones Ag-Cd en estado líquido. Se ha establecido el mecanismo metalúrgico que controla la formación del espesor cubierto con partículas de CdO producido por oxidación interna del material Ag-Cd/CdO. Se desarrolló con éxito una técnica de preparación metalográfica para caracterizar el tamaño y distribución de partículas de CdO producidas por oxidación interna sobre la superficie de cada lámina en función de la distancia a partir de la superficie original hasta el límite de partículas de CdO dispersas. Las placas del material fueron desbastadas secuencialmente sobre su superficie y se midió el espesor desbastado en la sección transversal de cada nueva superficie para determinar el número de partículas por unidad de área y el tamaño promedio de partícula.

N-myristoylated ubiquitin ligase Cbl-b inhibitor prevents on glucocorticoid-induced atrophy in mouse skeletal muscle.

Science.gov (United States)

Ochi, Arisa; Abe, Tomoki; Nakao, Reiko; Yamamoto, Yoriko; Kitahata, Kanako; Takagi, Marina; Hirasaka, Katsuya; Ohno, Ayako; Teshima-Kondo, Shigetada; Taesik, Gwag; Choi, Inho; Kawamura, Tomoyuki; Nemoto, Hisao; Mukai, Rie; Terao, Junji; Nikawa, Takeshi

2015-03-15

A DGpYMP peptide mimetic of tyrosine(608)-phosphorylated insulin receptor substrate-1 (IRS-1), named Cblin, was previously shown to significantly inhibit Cbl-b-mediated IRS-1 ubiquitination. In the present study, we developed N-myristoylated Cblin and investigated whether it was effective in preventing glucocorticoid-induced muscle atrophy. Using HEK293 cells overexpressing Cbl-b, IRS-1 and ubiquitin, we showed that the 50% inhibitory concentrations of Cbl-b-mediated IRS-1 ubiquitination by N-myristoylated Cblin and Cblin were 30 and 120 μM, respectively. Regarding the DEX-induced atrophy of C2C12 myotubes, N-myristoylated Cblin was more effective than Cblin for inhibiting the DEX-induced decreases in C2C12 myotube diameter and IRS-1 degradation. The inhibitory efficacy of N-myristoylated Cblin on IRS-1 ubiquitination in C2C12 myotubes was approximately fourfold larger than that of Cblin. Furthermore, N-myristoylation increased the incorporation of Cblin into HEK293 cells approximately 10-folds. Finally, we demonstrated that N-myristoylated Cblin prevented the wet weight loss, IRS-1 degradation, and MAFbx/atrogin-1 and MuRF-1 expression in gastrocnemius muscle of DEX-treated mice approximately fourfold more effectively than Cblin. Taken together, these results suggest that N-myristoylated Cblin prevents DEX-induced skeletal muscle atrophy in vitro and in vivo, and that N-myristoylated Cblin more effectively prevents muscle atrophy than unmodified Cblin. Copyright © 2015 Elsevier Inc. All rights reserved.

Discovery of 4-anilino-N-methylthieno[3,2-d]pyrimidines and 4-anilino-N-methylthieno[2,3-d]pyrimidines as potent apoptosis inducers.

Science.gov (United States)

Kemnitzer, William; Sirisoma, Nilantha; May, Chris; Tseng, Ben; Drewe, John; Cai, Sui Xiong

2009-07-01

We report the discovery of N-((benzo[d][1,3]dioxol-5-yl)methyl)-6-phenylthieno[3,2-d]pyrimidin-4-amine (2a) as an apoptosis inducer using our proprietary cell- and caspase-based ASAP HTS assay, and SAR study of HTS hit 2a which led to the discovery of 4-anilino-N-methylthieno[3,2-d]pyrimidines and 4-anilino-N-methylthieno[2,3-d]pyrimidines as potent apoptosis inducers. Compounds 5d and 5e were the most potent with EC(50) values of 0.008 and 0.004microM in T47D human breast cancer cells, respectively. Compound 5d was found to be highly active in the MX-1 breast cancer model. Functionally, compounds 5d and 5e both induced apoptosis through inhibition of tubulin polymerization.

Method of spectra parametrization of (n, x) and (n, nx) reactions induced by DT-neutrons

International Nuclear Information System (INIS)

Aleksandrov, D.V.; Kovrigin, B.S.

1980-01-01

A method for parmetrization of experimental spectra has been developed for more convenient carrying out a process of separating competing mechanisms contributions in spectra of the (n, x) and (n, nx) reactions induced with DT neutrons. Differential cross sections of competing partial processes are used. as expanding coefficients. Model spectra may be represented in the form of tabulated-given functions calculated separately from formulae of any complexity degree. Fit of model expressions is performed by the least square method (lsm). Step-by-step algorithm of nonlinear optimization is used for search for lsm- evaluations of theoretical models parameters [ru

El Grado en Medicina. Una visión por parte de los alumnos

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Alejandro Callizo Silvestre

2015-01-01

Full Text Available El Grado en Medicina es uno de los grados más demandados por parte de los alumnos, como así lo demuestra su elevada nota de corte. Esto hace que los aspirantes se vean sometidos a una gran presión. Por eso y por la necesidad de evaluar habilidades sociales y emocionales indispensables para la práctica médica, nos planteamos si el método actual es el mejor y si la introducción de una prueba específica para Medicina ayudaría a definir mejor el perfil de estudiantes, más allá de la excelencia académica. La visión de los alumnos sobre el Grado en Medicina es, en general, muy positiva, sin olvidar que existen muchos aspectos que mejorar, especialmente en metodologías que aseguren una mayor motivación por parte del estudiantado y una mayor adherencia a los estudios. Por ello, desde el Consejo Estatal de Estudiantes de Medicina (CEEM abogamos por la introducción de estrategias educativas alternativas que nos aparten del mero estudio pasivo, como son el aprendizaje basado en problemas, el aumento de peso en los planes de estudio de las prácticas clínicas, así como darle mayor importancia a aspectos no científicos del ámbito profesional como la bioética o las habilidades comunicativas. Además, consideramos esencial la evaluación de esta clase de competencias mediante la introducción de ECOE (evaluación clínica objetiva estructurada, debido a que es un método más fiable a la hora de evaluar competencias no teóricas.

La matematización de los procesos químicos. Primera parte

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Rómulo Gallego Badillo

2012-04-01

Full Text Available Dada la extensión del presente aporte se ha decidido dividirlo en dos partes. En la primera se adelanta una reconstrucción de la historia del modelo cinético molecular de los gases y de la termodinámica clásica, y se realiza una aproximación al análisis epistemológico. En la segunda se intenta también una reconstrucción histórica de la creación de la fisicoquímica como disciplina científica y la introducción de la mirada desde la termodinámica clásica de los procesos químicos, asumidos como sistemas y como “máquinas térmicas”. Se irá más allá de la inicialmente designada como “dinámica química”. El objetivo consiste en elaborar una explicación admisible que dé cuenta de la introducción en el discurso químico, de una matemática de mayor complejidad que la propia del álgebra, dentro de la cual se construyó, durante la segunda mitad del siglo XIX, la química como ciencia, construcción ésta basada en las leyes ponderales.

Description of histopathological changes induced by the venom of the Persian Gulf Lionfish (Pterois russelli) in a mouse model of multiorgan toxicity.

Science.gov (United States)

Memar, Bahareh; Jamili, Shahla; Shahbazzadeh, Delavar; Pooshang Bagheri, Kamran

2016-11-01

Pterois russelli is a venomous fish belongs to Scorpaenidae family. Envenomation by the Persian Gulf lionfish is associated with local pain, marked inflammation and local heat. The present study was aimed to document the histopathological changes in liver, heart, lung, kidney and alterations in release of critical enzymes such as LDH, CK. AST, ALT and ALP induced by the administration of various doses of P. russelli venom in a mouse model. LD50 of venom was determined by intravenous injection in Balb/c mice. Histopathological alterations of lung, liver, heart and kidney following injection of one LD50, 1/2 and 1/3 LD50 doses of the venom were evaluated. Simultaneously, release of LDH, CK, AST, ALT and ALP were measured in serum following administration of 1/2 and1/3 LD50 doses of the venom too. LD50 was calculated as 10.5 mg/kg. The level of all enzymes were increased after 3 h and significantly raised after 24 h and rapidly reduced after 48 h. Histological studies showed that one LD50 and 1/2 LD50 doses of the venom induced significant histological alterations in the lungs, liver, heart and kidneys including congestion, hemorrhage, necrosis, apoptosis, edema, and infiltration of inflammatory cells. The results indicate that the venom of P. russelli has nephrotoxic, hepatotoxic, cardiotoxic and pneumotoxic effects in mouse model. Among four examined vital organs, the highest critical events were seen in liver. The findings are useful to give new insight in the fish's venom studies. Gathering the data resulted from this study together will be directed us toward a good aspect concerning the toxicity of potential therapeutic molecules in the venom of lionfish. Copyright © 2016 Elsevier Ltd. All rights reserved.

Axial p-n junction and space charge limited current in single GaN nanowire

Science.gov (United States)

Fang, Zhihua; Donatini, Fabrice; Daudin, Bruno; Pernot, Julien

2018-01-01

The electrical characterizations of individual basic GaN nanostructures, such as axial nanowire (NW) p-n junctions, are becoming indispensable and crucial for the fully controlled realization of GaN NW based devices. In this study, electron beam induced current (EBIC) measurements were performed on two single axial GaN p-n junction NWs grown by plasma-assisted molecular beam epitaxy. I-V characteristics revealed that both ohmic and space charge limited current (SCLC) regimes occur in GaN p-n junction NW. Thanks to an improved contact process, both the electric field induced by the p-n junction and the SCLC in the p-part of GaN NW were disclosed and delineated by EBIC signals under different biases. Analyzing the EBIC profiles in the vicinity of the p-n junction under 0 V and reverse bias, we deduced a depletion width in the range of 116-125 nm. Following our previous work, the acceptor N a doping level was estimated to be 2-3 × 1017 at cm-3 assuming a donor level N d of 2-3 × 1018 at cm-3. The hole diffusion length in n-GaN was determined to be 75 nm for NW #1 and 43 nm for NW #2, demonstrating a low surface recombination velocity at the m-plane facet of n-GaN NW. Under forward bias, EBIC imaging visualized the electric field induced by the SCLC close to p-side contact, in agreement with unusual SCLC previously reported in GaN NWs.

Axial p-n junction and space charge limited current in single GaN nanowire.

Science.gov (United States)

Fang, Zhihua; Donatini, Fabrice; Daudin, Bruno; Pernot, Julien

2018-01-05

The electrical characterizations of individual basic GaN nanostructures, such as axial nanowire (NW) p-n junctions, are becoming indispensable and crucial for the fully controlled realization of GaN NW based devices. In this study, electron beam induced current (EBIC) measurements were performed on two single axial GaN p-n junction NWs grown by plasma-assisted molecular beam epitaxy. I-V characteristics revealed that both ohmic and space charge limited current (SCLC) regimes occur in GaN p-n junction NW. Thanks to an improved contact process, both the electric field induced by the p-n junction and the SCLC in the p-part of GaN NW were disclosed and delineated by EBIC signals under different biases. Analyzing the EBIC profiles in the vicinity of the p-n junction under 0 V and reverse bias, we deduced a depletion width in the range of 116-125 nm. Following our previous work, the acceptor N a doping level was estimated to be 2-3 × 10 17 at cm -3 assuming a donor level N d of 2-3 × 10 18 at cm -3 . The hole diffusion length in n-GaN was determined to be 75 nm for NW #1 and 43 nm for NW #2, demonstrating a low surface recombination velocity at the m-plane facet of n-GaN NW. Under forward bias, EBIC imaging visualized the electric field induced by the SCLC close to p-side contact, in agreement with unusual SCLC previously reported in GaN NWs.

Fast-ion transport induced by Alfvén eigenmodes in the ASDEX Upgrade tokamak

DEFF Research Database (Denmark)

Garcia-Munoz, M.; Classen, I.G.J.; Geiger, B.

2011-01-01

A comprehensive suite of diagnostics has allowed detailed measurements of the Alfvén eigenmode (AE) spatial structure and subsequent fast-ion transport in the ASDEX Upgrade (AUG) tokamak [1]. Reversed shear Alfvén eigenmodes (RSAEs) and toroidal induced Alfvén eigenmodes (TAEs) have been driven u...

Cadmium inhibits repair of UV-, methyl methanesulfonate- and N-methyl-N-nitrosourea-induced DNA damage in Chinese hamster ovary cells

International Nuclear Information System (INIS)

Fatur, Tanja; Lah, Tamara T.; Filipic, Metka

2003-01-01

The co-genotoxic effects of cadmium are well recognized and it is assumed that most of these effects are due to the inhibition of DNA repair. We used the comet assay to analyze the effect of low, non-toxic concentrations of CdCl 2 on DNA damage and repair-induced in Chinese hamster ovary (CHO) cells by UV-radiation, by methyl methanesulfonate (MMS) and by N-methyl-N-nitrosourea (MNU). The UV-induced DNA lesions revealed by the comet assay are single-strand breaks which are the intermediates formed during nucleotide excision repair (NER). In cells exposed to UV-irradiation alone the formation of DNA strand breaks was rapid, followed by a fast rejoining phase during the first 60 min after irradiation. In UV-irradiated cells pre-exposed to CdCl 2 , the formation of DNA strand breaks was significantly slower, indicating that cadmium inhibited DNA damage recognition and/or excision. Methyl methanesulfonate and N-methyl-N-nitrosourea directly alkylate nitrogen and oxygen atoms of DNA bases. The lesions revealed by the comet assay are mainly breaks at apurinic/apyrimidinic (AP) sites and breaks formed as intermediates during base excision repair (BER). In MMS treated cells the initial level of DNA strand breaks did not change during the first hour of recovery; thereafter repair was detected. In cells pre-exposed to CdCl 2 the MMS-induced DNA strand breaks accumulated during the first 2 h of recovery, indicating that AP sites and/or DNA strand breaks were formed but that further steps of BER were blocked. In MNU treated cells the maximal level of DNA strand breaks was detected immediately after the treatment and the breaks were repaired rapidly. In CdCl 2 pre-treated cells the formation of MNU-induced DNA single-strand breaks was not affected, while the repair was slower, indicating inhibition of polymerization and/or the ligation step of BER. Cadmium thus affects the repair of UV-, MMS- and MNU-induced DNA damage, providing further evidence, that inhibition of DNA repair

Apoptosis and radiosensitivity induced by N-acety1 phytosphingosine, in human cancer cell line

International Nuclear Information System (INIS)

Kim, Y. H.; Kim, K. S.; Han, Y. S.; Jeon, S. J.; Song, J. Y.; Jung, I. S.; Hong, S. H.; Yun, Y. S.; Park, J. S.

2004-01-01

Ceramide is a key lipid molecule in signal transduction with a role in various regulatory pathways including differentiation, proliferation and especially apoptosis. Ionizing radiation-induced apoptosis is associated with accumulation of ceramide, and the sphingomyelinase deficiency results in radioresistance. We investigated the exogenous treatment of N-acetyl-phytosphingosine (NAPS), an analogue of N-acetyl-sphingosine (C 2 -Ceramide), and C 2 -ceramide exert apoptotic effect on human T cell lymphoma Jurkat cells and breast cancer cell line MDA-MB-231. NAPS and C 2 -Ceramide has cytotoxic effect in time- and dose-dependent manner, and increased caspase-3, 8 activity. However, NAPS induced apoptosis more effectively, and increased caspase activity induced by NAPS is more higher than C 2 -ceramide. Moreover, NAPS decreased clonogenicity of irradiated cells and increased radiation-induced apoptosis significantly. Increased cell death by irradiation in the presence of NAPS is owing to the increase of caspase activity. These data suggest that NAPS might be used for lead as a new type of radiosensitizing agent increasing radiation-induced apoptosis

Antibacterianos de acción sistémica: Parte I. Antibióticos betalactámicos

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Manuel Cué Brugueras

1998-08-01

Full Text Available Se presenta una revisión bibliográfica sobre los antibacterianos de acción sistémica, de los cuales en esta primera parte se desarrolla la de los antibióticos betalactámicos, así como algunos conceptos básicos y los diferentes tipos de clasificación de los antibióticos en general. Se abordan los derivados penicilánicos y cafalosporánicos más conocidos internacionalmenteA literature review on systemic antibacterial drugs is presented. This first part includes beta-lactam antibiotics, some basic concepts and the different types of antibiotic classification in general. The most known penicilim and cephalosporin derivates worlwide are dealt with

Chronic ethanol exposure induces SK-N-SH cell apoptosis by increasing N-methyl-D-aspartic acid receptor expression and intracellular calcium.

Science.gov (United States)

Wang, Hongbo; Wang, Xiaolong; Li, Yan; Yu, Hao; Wang, Changliang; Feng, Chunmei; Xu, Guohui; Chen, Jiajun; You, Jiabin; Wang, Pengfei; Wu, Xu; Zhao, Rui; Zhang, Guohua

2018-04-01

It has been identified that chronic ethanol exposure damages the nervous system, particularly neurons. There is scientific evidence suggesting that neuronal loss caused by chronic ethanol exposure has an association with neuron apoptosis and intracellular calcium oscillation is one of the primary inducers of apoptosis. Therefore, the present study aimed to investigate the inductive effects of intracellular calcium oscillation on apoptosis in SK-N-SH human neuroblastoma cells and the protective effects of the N-methyl-D-aspartic acid receptor (NMDAR) antagonist, memantine, on SK-N-SH cell apoptosis caused by chronic ethanol exposure. SK-N-SH cells were treated with 100 mM ethanol and memantine (4 µM) for 2 days. Protein expression of NR1 was downregulated by RNA interference (RNAi). Apoptosis was detected by Annexin V/propidium iodide (PI) double-staining and flow cytometry and cell viability was detected using an MTS kit. Fluorescence dual wavelength spectrophotometry was used to determine the intracellular calcium concentration and the levels of NR1 and caspase-3 were detected using western blotting. NR1 mRNA levels were also detected using qPCR. It was found that chronic ethanol exposure reduced neuronal cell viability and caused apoptosis of SK-N-SH cells, and the extent of damage in SK-N-SH cells was associated with ethanol exposure concentration and time. In addition, chronic ethanol exposure increased the concentration of intracellular calcium in SK-N-SH cells by inducing the expression of NMDAR, resulting in apoptosis, and memantine treatment reduced ethanol-induced cell apoptosis. The results of the present study indicate that the application of memantine may provide a novel strategy for the treatment of alcoholic dementia.

Parton saturation and $N_{part}$ scaling of semi-hard processes in QCD

CERN Document Server

Kharzeev, Dima E; McLerran, L; 10.1016/S0370-2693(03)00420-9

2003-01-01

We argue that the suppression of high p/sub t/ hadrons discovered recently in heavy ion collisions at RHIC may be a consequence of saturation in the color glass condensate. We qualitatively and semi- quantitatively describe the data, in particular, the dependence upon the number of nucleon participants. We show that if parton saturation sets in at sufficiently small energy, then in nucleus-nucleus collisions at RHIC and LHC energies the cross sections of semi-hard processes should scale approximately with the number of participants, N/sub part/. Our results provide a possible explanation of both the absence of apparent jet quenching at SPS energies and its presence at RHIC. Under the same assumption we predict that in semi-central and central pA (dA) collisions at collider energies the dependence of semi-hard processes on the number of participating nucleons of the nucleus will change to ~(N/sub part//sup A/)/sup 1/2/. The forthcoming data on dA collisions will provide a crucial test of this description. (61 ...

DECLARACIÓN DE LA PARTE COMO MEDIO DE PRUEBA Party as witness

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Felipe Marín Verdugo

2010-01-01

Full Text Available Los procedimientos judiciales chilenos han sufrido importantes cambios en las últimas dos décadas. Han transitado desde un sistema escrito a uno por audiencias. Esto ha significado un nuevo diseño de la audiencia de juicio y en particular, de las reglas de la prueba. El alcance de estos cambios no es aun totalmente comprendido, lo que permite la sobrevivencia de algunas prácticas del sistema escrito anterior dentro del nuevo. Este trabajo identifica una de ellas, que consiste en la exclusión de las partes como testigos en sus propios juicios. Se explicará cuál fue el fundamento de esta exclusión en el sistema escrito anterior y cómo éste ha sido superado en varios ordenamientos comparados. Se sostendrá que en el contexto de los nuevos sistemas por audiencias chilenos, en los que el juez debe valorar la prueba en concreto, dicha exclusión carece de sentido y las partes deben ser admitidas para declarar voluntariamente. Se sostendrá también que las nuevas reglas de la prueba lo permiten, analizándolas pormenorizadamente. Asimismo se contestará a los argumentos esgrimidos para justificar la mantención de esta exclusión y finalmente, se propondrá una manera de rendir la declaración de la parte como testigo en conformidad a las nuevas reglas de la prueba.During the last two decades, the Chilean judicial procedures have undergone an important reform process. It went from a written procedure to a hearing-based procedure. This change involved a new design for the trial hearing and, in particular, for the rules of evidence. The meaning of these changes is not yet well understood, making it easier for the survival of former practices of the written system within the new hearing-based system. This paper identifies on of them, which is the exclusion of parties as witnesses. The paper explains the reasons of the origin of this rule of exclusion in the former written procedure and how it was subsequently overcome in several comparative

Auto-inducing media for uniform isotope labeling of proteins with 15N, 13C and 2H

International Nuclear Information System (INIS)

Guthertz, Nicolas; Klopp, Julia; Winterhalter, Aurélie; Fernández, César; Gossert, Alvar D.

2015-01-01

Auto-inducing media for protein expression offer many advantages like robust reproducibility, high yields of soluble protein and much reduced workload. Here, an auto-inducing medium for uniform isotope labelling of proteins with 15 N, 13 C and/or 2 H in E. coli is presented. So far, auto-inducing media have not found widespread application in the NMR field, because of the prohibitively high cost of labeled lactose, which is an essential ingredient of such media. Here, we propose using lactose that is only selectively labeled on the glucose moiety. It can be synthesized from inexpensive and readily available substrates: labeled glucose and unlabeled activated galactose. With this approach, uniformly isotope labeled proteins were expressed in unattended auto-inducing cultures with incorporation of 13 C, 15 N of 96.6 % and 2 H, 15 N of 98.8 %. With the present protocol, the NMR community could profit from the many advantages that auto-inducing media offer

High-electric-field-stress-induced degradation of SiN passivated AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Wen-Ping, Gu; Huan-Tao, Duan; Jin-Yu, Ni; Yue, Hao; Jin-Cheng, Zhang; Qian, Feng; Xiao-Hua, Ma

2009-01-01

AlGaN/GaN high electron mobility transistors (HEMTs) are fabricated by employing SiN passivation, this paper investigates the degradation due to the high-electric-field stress. After the stress, a recoverable degradation has been found, consisting of the decrease of saturation drain current I Dsat , maximal transconductance g m , and the positive shift of threshold voltage V TH at high drain-source voltage V DS . The high-electric-field stress degrades the electric characteristics of AlGaN/GaN HEMTs because the high field increases the electron trapping at the surface and in AlGaN barrier layer. The SiN passivation of AlGaN/GaN HEMTs decreases the surface trapping and 2DEG depletion a little during the high-electric-field stress. After the hot carrier stress with V DS = 20 V and V GS = 0 V applied to the device for 10 4 sec, the SiN passivation decreases the stress-induced degradation of I Dsat from 36% to 30%. Both on-state and pulse-state stresses produce comparative decrease of I Dsat , which shows that although the passivation is effective in suppressing electron trapping in surface states, it does not protect the device from high-electric-field degradation in nature. So passivation in conjunction with other technological solutions like cap layer, prepassivation surface treatments, or field-plate gate to weaken high-electric-field degradation should be adopted. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

N-acetylcysteine enhances nitroglycerin-induced headache and cranial arterial responses

DEFF Research Database (Denmark)

Iversen, Helle Klingenberg

1992-01-01

The effects of N-acetylcysteine, a sulfhydryl group donor, on nitroglycerin-induced headache and dilation of temporal and radial arteries were investigated in 11 healthy volunteers. Nitroglycerin, 0.06 microgram/kg/min, was infused for 20 minutes immediately after and 120 minutes after pretreatment...... response (median headache score, 3 versus 1), and the headache retained its vascular characteristics. Temporal artery dilation was also potentiated by N-acetylcysteine, 139% +/- 3% versus 127% +/- 3% of baseline, whereas the radial artery was unaffected. The potentiation was most pronounced after the first...... nitroglycerin infusion (12% versus 4.5% compared with placebo). A prolonged dilation of the temporal artery was observed only after the first nitroglycerin infusion, when high levels of N-acetylcysteine were present....

Solution of equation for imaginary part of forward scattering amplitude for theories with lambdaphisup(n) interaction

International Nuclear Information System (INIS)

Arbuzov, B.A.; D'yakonov, V.Yu.; Rochev, V.E.

1975-01-01

Solution of equations for imaginary part of forward scattering amplitude in ladder approximation for theories with lambdaphisup(n),n(>=)4 interaction have been obtained. Two types of diagrams have been considered for lambdaphisup(n) renormalizable theory. It is shown, that the leading singularity is the branch point, which gives the power asymptotics with accuracy up to logarithms. The unrenormalizable theory with n(>=)5 lead to exponentially rising asymptotics

Contaminación atmosférica por partículas y salud en Valencia, 1994-1996

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Ballester F.

2002-01-01

Full Text Available Objetivo: Estimar la asociación a corto plazo entre los valores de contaminación atmosférica por partículas en suspensión y diferentes indicadores de morbilidad y mortalidad en la ciudad de Valencia. Métodos: Estudio ecológico de series temporales en el que se relacionan las variaciones diarias en los valores de contaminación atmosférica por humos negros e indicadores de mortalidad, ingresos hospitalarios y visitas a urgencias en la ciudad de Valencia, durante el período 1994-1996. La magnitud de la asociación se estimó mediante regresión autorregresiva de Poisson utilizando modelos aditivos generalizados. Se examinó la forma de la relación, el efecto retardado de la contaminación y la posible modificación de efecto por otros contaminantes o períodos del año. Resultados: Existe una asociación significativa entre los valores de partículas en suspensión y varios indicadores analizados en Valencia. La forma de dicha relación es lineal. Un incremento de 10 μg/m³ en los valores diarios de humos negros se asoció con un incremento del 1,8% (intervalo de confianza [IC] del 95%, 0,9-2,7% en el número de defunciones del día siguiente. El mismo incremento en la contaminación se asoció con un aumento del 1,5% (0,1-2,8% en las defunciones por causa circulatoria, en un 1,3% (0,0-2,6% en los ingresos por causas circulatorias y en un 5,4 (0,6-10,4% en el número de visitas a urgencias por asma. Esta asociación no está confundida por los valores de otros contaminantes. No se encontró asociación de los humos negros con la mortalidad por enfermedades respiratorias, los ingresos hospitalarios por enfermedades cerebrovasculares ni las visitas a urgencias por enfermedad pulmonar obstructiva crónica (EPOC. Conclusiones: Este estudio proporciona evidencia de que los valores de partículas en suspensión en Valencia se asocian con las urgencias por asma, los ingresos por enfermedades circulatorias y las defunciones diarias. La asociación

Fast-neutron-induced fission of 242Pu at nELBE

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Kögler Toni

2017-01-01

Full Text Available The fast neutron-induced fission cross section of 242Pu was determined in the range of 0.5 MeV to 10 MeV relative to 235U(n,f at the neutron time-of-flight facility nELBE. The number of target nuclei was calculated by means of measuring the spontaneous fission rate of 242Pu. Neutron transport simulations with Geant4 and MCNP6 are used to correct the relative cross section for neutron scattering. The determined results are in good agreement with current experimental and evaluated data sets.

La Canción Española: ¿como puede llegar a formar parte de la programacción en los auditorios del Mundo?

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Nan Maro Babakhanian

2014-01-01

Full Text Available El presente artículo proporciona una valoración de la información disponible en este momento sobre la interpretación de las canciones artísticas de época romántica, post-romántica y contemporánea en español (poemas en castellano. La canción artística española sólo podrá llegar a formar parte del Repertorio estándar en los conservatorios, en otros programas para el estudio de la música y en la programación de recitales en auditorios en todas partes del mundo, cuando los demás artistas y profesores de música sepan de su existencia y de cómo interpretarla]. Se incluye una evaluación de las herramientas didácticas que tendrían que establecerse para asegurar que este amplísimo y variado repertorio se incluya en las asignaturas comunes de todos los músicos líricos (los cantantes, pianistas y directores.

Effects of Dietary Xanthophylls, Canthaxanthin and Astaxanthin on N-Methyl-N-nitrosourea-induced Rat Mammary Carcinogenesis.

Science.gov (United States)

Yuri, Takashi; Yoshizawa, Katsuhiko; Emoto, Yuko; Kinoshita, Yuichi; Yuki, Michiko; Tsubura, Airo

Natural xanthophylls, canthaxanthin and astaxanthin are known to exhibit anticancer activity. However, the dietary effects of canthaxanthin and astaxanthin on N-methyl-N-nitrosourea (MNU)-induced mammary cancer remain controversial, and their mechanisms of action have not been clearly identified. Three-week-old female Sprague-Dawley rats were fed a xanthophyll-free (basal diet) diet or experimental diets containing canthaxanthin or astaxanthin (0.04% and 0.4%) for 5 weeks (until 8 weeks of age), after which all rats were provided the basal diet (n=15 each). Rats were administered MNU at 6 weeks of age, and the incidence of mammary tumors at 20 weeks of age was compared. The expression of adiponectin in mammary adipose tissues taken at 7 weeks of age was also compared. Compared to the basal diet group, the 0.4% (but not the 0.04%) astaxanthin diet significantly reduced the incidence of palpable mammary carcinoma (92% vs. 42%; p<0.05), while the low and high canthaxanthin diets produced no significant inhibition. Adiponectin immunoblotting showed significantly higher expression in the 0.4% astaxanthin diet group, while the other groups were similar to the basal diet group. High concentrations of astaxanthin suppress MNU-induced mammary carcinoma. Changes in adiponectin may be involved in the mechanism of action. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

N,N-dimethyl phytosphingosine induces caspase-8-dependent cytochrome c release and apoptosis through ROS generation in human leukemia cells

International Nuclear Information System (INIS)

Kim, Byeong Mo; Choi, Yun Jung; Han, Youngsoo; Yun, Yeon-Sook; Hong, Sung Hee

2009-01-01

N,N-dimethyl phytosphingosine (DMPS) blocks the conversion of sphingosine to sphingosine-1-phosphate (S1P) by the enzyme sphingosine kinase (SK). In this study, we elucidated the apoptotic mechanisms of DMPS action on a human leukemia cell line using functional pharmacologic and genetic approaches. First, we demonstrated that DMPS-induced apoptosis is evidenced by nuclear morphological change, distinct internucleosomal DNA fragmentation, and an increased sub-G1 cell population. DMPS treatment led to the activation of caspase-9 and caspase-3, accompanied by the cleavage of poly(ADP-ribose) polymerase (PARP) and led to cytochrome c release, depolarization of the mitochondrial membrane potential, and downregulation of the anti-apoptotic members of the bcl-2 family. Ectopic expression of bcl-2 and bcl-xL conferred resistance of HL-60 cells to DMPS-induced cell death, suggesting that DMPS-induced apoptosis occurs predominantly through the activation of the intrinsic mitochondrial pathway. We also observed that DMPS activated the caspase-8-Bid-Bax pathway and that the inhibition of caspase-8 by z-IETD-fmk or small interfering RNA suppressed the cleavage of Bid, cytochrome c release, caspase-3 activation, and apoptotic cell death. In addition, cells subjected to DMPS exhibited significantly increased reactive oxygen species (ROS) generation, and ROS scavengers, such as quercetin and Tiron, but not N-acetylcysteine (NAC), inhibited DMPS-induced activations of caspase-8, -3 and subsequent apoptotic cell death, indicating the role of ROS in caspase-8-mediated apoptosis. Taken together, these results indicate that caspase-8 acts upstream of caspase-3, and that the caspase-8-mediated mitochondrial pathway is important in DMPS-induced apoptosis. Our results also suggest that ROS are critical regulators of caspase-8-mediated apoptosis in DMPS-treated leukemia cells.

Contribución para un estado de la cuestión sobre el uso de condón en relaciones sexuales comerciales por parte de trabajadores(as del sexo

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Eduardo Pérez Archundia

Full Text Available El presente artículo busca ofrecer una compilación de investigaciones realizadas - principalmente en México- sobre el uso del condón en el marco de relaciones sexuales comerciales. Se procura contribuir, con este estado de la cuestión acerca del conocimiento que ha logrado acumularse en torno a los factores que determinarían el uso o no uso de condón por parte de trabajadores(as del sexo, a las reflexiones en torno de la prevención del VIH/SIDA.

Traducción y tecnología. Análisis del uso y percepción de wikipedia por parte de los profesionales de la traducción

OpenAIRE

Alonso Jiménez, Elisa

2014-01-01

Esta tesis doctoral representa una aproximación inter y transdisciplnar al análisis del binomio traducción y tecnología, tanto desde un punto de vista teórico como práctico, y está centrado en el uso y percepción de Wikipedia en el contexto de la traducción profesional. Los principales resultados y conclusiones de este trabajo se presentan siguiendo una estructura de tres niveles que deriva de los objetivos específicos de la tesis: Objetivo de la primera parte (A): Revisar las propuest...

Ga induced superstructures as templates for lattice matched hetroepitaxial growth of GaN on Si(111) substrate

International Nuclear Information System (INIS)

Kumar, Praveen; Kuyyalil, Jithesh; Shivaprasad, S. M.

2010-01-01

High quality GaN is grown by plasma assisted molecular beam epitaxy on Ga induced superstructural phases of Si(111)7x7. Three stable surface phases induced by Ga adsorption, viz., (1x1), (6.3x6.3), and (√3x√3)R30 deg., are employed as templates to grow epitaxial (0001) GaN thin films. GaN grown on Si(√3x√3)R30 deg. -Ga is found to be highly crystalline with intense (0002) x-ray diffraction and photoluminescence peaks with low full width at half maximum, low surface roughness, and stoichiometric surface composition. The high quality of these GaN films formed at a low temperature of 400 deg. C is explained by the integral (x2) lattice matching between the unit cell of GaN and the (√3x√3) phase. The experiments demonstrate a plausible approach of adsorbate induced surface modifications as templates for III-V hetroepitaxy on Si surfaces.

Rhodosporidium toruloides BANNO: Dose-response relationship, mutagenic efficiency and spectrum of mutants of auxotrophy-producing mutations induced by ultraviolet light and N-methyl-N'-nitro-N-nitrosoguanidine

International Nuclear Information System (INIS)

Boettcher, F.; Samsonova, I.A.

1978-01-01

The kinetics, efficiency, and specificity of induction of forward mutations to auxotrophy by ultraviolet light (UV) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was examined in stationary phase cells of Rhodosporidium (Rhodotorula) wild strain Rg1. In comparison to the spontaneous level the frequency of auxotrophic mutants was increased more than 1000 times by both mutagens, however, the mutagenic efficiency of MNNG was higher than that of UV. We found that the forward mutation rate is a linear function of the applicated UV and MNNG doses in the range to 600 J m -2 or 25 mM x min, respectively. The 35 studied biosynthetic pathways to amino acids, purines, pyrimidines, and vitamins are genetically blocked at different frequencies, but there is not any significant difference between UV and MNNG induced frequencies of mutants with a specific requirement. However, in difference to the approximately equal distribution of the MNNG-induced nic mutants among the genetic blocks of the tryptophan-nicotinamide pathway, UV-induced nic mutants occurred with a higher frequency in the genes of the tryptophan pyrrolase and the 3-hydroxykynureninase than in the genes of the other enzymes of the pathway. (author)

Antibacterianos de acción sistémica: Parte II. Otros grupos de antibióticos

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Manuel Cué Brugueras

1998-08-01

Full Text Available Se presenta la segunda parte de una revisión bibliográfica sobre los antibacterianos de acción sistémica, la cual incluye grupos de antibióticos tan importantes como aminociclitoles, aminoglucósidos, diaminopirimidinas, estreptograminas, fosfomicinas, fusidanos, glicopéptidos, lincosamidas, macrólidos, nitrofuranos, nitroimidazoles, polipéptios, quinolonas y rifamicinasThe second part of the literature review on systemic antibacterial drugs is presented. It deals with such important groups of antibiotics as aminociclitol, aminoglycosides, diaminopirimidine, streptogramin, fosfomycin, fusidane, glycopeptides, lincosamides, macrolides, nitrofurans, nitroimidazols, polypeptides, quinolones, and rifamycins

Lattice damage induced by Tb-implanted AlN crystalline films

International Nuclear Information System (INIS)

Lu Fei; Hu Hui; Rizzi, A.

2002-01-01

AlN films with thickness from 100 to 1000 nm were grown on SiC substrate by MBE. AlN crystalline films were doped by implantation with 160 keV Tb ions to fluences of 5x10 14 , 1.5x10 15 , 3x10 15 and 6x10 15 ions/cm 2 , respectively. The damage profiles in AlN films induced by Tb implantation were investigated using RBS/channeling technique. A procedure developed by Feldman and Rodgers was used to extract damage profile by considering the dechanneling mechanism of multiple. The comparison of the extracted profile with TRIM prediction shows a significant difference in the shape and in the position of damage profile. The damage profile in AlN film is similar as Tb distribution. The RBS/channeling of Tb-implanted AlN film before and after 950 deg. C annealing treatments show a good consistency, which indicate that high temperature annealing cannot result in a significant change in both crystal damage and in Tb distribution

Integrating Topographic Measures to Explore the Protective Effects of Peonidin Against the N-Methyl-N-Nitrosourea Induced Photoreceptor Degeneration

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Ye Tao

2016-02-01

Full Text Available Background/Aims: The pathphysiological properties of N-Methyl -N -nitrosourea (MNU induced photoreceptor degeneration are similar to the hereditary retinitis pigmentosa (RP. The present study sought to explore the beneficial effects of the peonidin, a common aglycone form of anthocyanin, on the MNU induced photoreceptor degeneration via topographic measurements. Methods: The MNU administrated mouse received peonidin or vehicle injections, and then they were examined by electroretinography (ERG, multi electrode array (MEA, histological and immunohistochemistry studies. Results: The protective effects of peonidin on the MNU administrated retinas were systematically verified and quantified by topographic measures. The peonidin treatment could protect the photoreceptor against the MNU toxicity both functionally and morphologicaly. The most sensitive zone to peonidin therapy was sorted out, indicating that different rescuing kinetics existed between the retinal hemispheres and retinal quadrants. Moreover, the hyperactive spontaneous firing response and the debilitated light induced response in MNU administrated retinas could be partially reversed by peonidin treatment. To our knowledge, this was the first study to explore the pharmacological effects of peonidin on the electrophysiological properties of inner visual signal pathways. Conclusion: The peonidin could ameliorate the MNU induced photoreceptors degeneration and rectify the abnormities in the inner visual signal pathways. Future refinements of the knowledge cast insights into the discovery of a novel treatment for human RP.

Mesenchymal stromal cell treatment prevents H9N2 avian influenza virus-induced acute lung injury in mice

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Yan Li

2016-10-01

Full Text Available Abstract Background The avian influenza virus (AIV can cross species barriers and expand its host range from birds to mammals, even humans. Avian influenza is characterized by pronounced activation of the proinflammatory cytokine cascade, which perpetuates the inflammatory response, leading to persistent systemic inflammatory response syndrome and pulmonary infection in animals and humans. There are currently no specific treatment strategies for avian influenza. Methods We hypothesized that mesenchymal stromal cells (MSCs would have beneficial effects in the treatment of H9N2 AIV-induced acute lung injury in mice. Six- to 8-week-old C57BL/6 mice were infected intranasally with 1 × 104 MID50 of A/HONG KONG/2108/2003 [H9N2 (HK] H9N2 virus to induce acute lung injury. After 30 min, syngeneic MSCs were delivered through the caudal vein. Three days after infection, we measured the survival rate, lung weight, arterial blood gas, and cytokines in both bronchoalveolar lavage fluid (BALF and serum, and assessed pathological changes to the lungs. Results MSC administration significantly palliated H9N2 AIV-induced pulmonary inflammation by reducing chemokines and proinflammatory cytokines levels, as well as reducing inflammatory cell recruit into the lungs. Thus, H9N2 AIV-induced lung injury was markedly alleviated in mice treated with MSCs. Lung histopathology and arterial blood gas analysis were improved in mice with H9N2 AIV-induced lung injury following MSC treatment. Conclusions MSC treatment significantly reduces H9N2 AIV-induced acute lung injury in mice and is associated with reduced pulmonary inflammation. These results indicate a potential role for MSC therapy in the treatment of clinical avian influenza.

Acetaminophen-induced Liver Injury is Attenuated in Transgenic fat-1 Mice Endogenously Synthesizing Long-chain n-3 Fatty Acids.

Science.gov (United States)

Feng, Ruibing; Wang, Yang; Liu, Conghui; Yan, Chunyan; Zhang, Hang; Su, Huanxing; Kang, Jing X; Shang, Chang-Zhen; Wan, Jian-Bo

2018-04-18

Acetaminophen (APAP) overdose-caused hepatotoxicity is the most commonly cause of drugs-induced liver failurecharacterized by oxidative stress, mitochondrial dysfunction, and cell damage. Therapeutic efficacy of omega-3 polyunsaturated fatty acids (n-3 PUFAs) in several models of liver disease is well documented. However, the impacts of n-3 PUFA on APAP hepatotoxicity are not adequately addressed. In this study, the fat-1 transgenic mice that synthesize endogenous n-3 PUFA and wild type (WT) littermates were injected intraperitoneally with APAP at the dose of 400 mg/kg to induce liver injury, and euthanized at 0 h, 2 h, 4 h and 6 h post APAP injection for sampling. APAP overdose caused severe liver injury in WT mice as indicated by serum parameters, histopathological changes and hepatocyte apoptosis, which were remarkably ameliorated in fat-1 mice. These protective effects of n-3 PUFA were associated with regulation of the prolonged JNK activation via inhibition of apoptosis signal-regulating kinase 1 (ASK1) / mitogen-activated protein kinase kinase 4 (MKK4) pathway. Additionally, the augment of endogenous n-3 PUFA reduced nuclear factor kappa B (NF-κB) - mediated inflammation response induced by APAP treatment in the liver. These findings indicate that n-3 PUFA has potent protective effects against APAP-induced acute liver injury, suggesting that n-3 dietary supplement with n-3 PUFA may be a potential therapeutic strategy for the treatment of hepatotoxicity induced by APAP overdose. Copyright © 2018 Elsevier Inc. All rights reserved.

Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

KAUST Repository

Yan, Long

2018-05-03

Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

Polarization-induced hole doping in N-polar III-nitride LED grown by metalorganic chemical vapor deposition

KAUST Repository

Yan, Long; Zhang, Yuantao; Han, Xu; Deng, Gaoqiang; Li, Pengchong; Yu, Ye; Chen, Liang; Li, Xiaohang; Song, Junfeng

2018-01-01

Polarization-induced doping has been shown to be effective for wide-bandgap III-nitrides. In this work, we demonstrated a significantly enhanced hole concentration via linearly grading an N-polar AlxGa1-xN (x = 0–0.3) layer grown by metal-organic chemical vapor deposition. The hole concentration increased by ∼17 times compared to that of N-polar p-GaN at 300 K. The fitting results of temperature-dependent hole concentration indicated that the holes in the graded p-AlGaN layer comprised both polarization-induced and thermally activated ones. By optimizing the growth conditions, the hole concentration was further increased to 9.0 × 1017 cm−3 in the graded AlGaN layer. The N-polar blue-violet light-emitting device with the graded p-AlGaN shows stronger electroluminescence than the one with the conventional p-GaN. The study indicates the potential of the polarization doping technique in high-performance N-polar light-emitting devices.

Ion irradiation-induced swelling and hardening effect of Hastelloy N alloy

Energy Technology Data Exchange (ETDEWEB)

Zhang, S.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, D.H.; Chen, H.C.; Lei, G.H.; Huang, H.F.; Zhang, W.; Wang, C.B. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Yan, L., E-mail: yanlong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Fu, D.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Tang, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2017-06-15

The volumetric swelling and hardening effect of irradiated Hastelloy N alloy were investigated in this paper. 7 MeV and 1 MeV Xe ions irradiations were performed at room temperature (RT) with irradiation dose ranging from 0.5 to 27 dpa. The volumetric swelling increases with increasing irradiation dose, and reaches up to 3.2% at 27 dpa. And the irradiation induced lattice expansion is also observed. The irradiation induced hardening initiates at low ion dose (≤1dpa) then saturates with higher ion dose. The irradiation induced volumetric swelling may be ascribed to excess atomic volume of defects. The irradiation induced hardening may be explained by the pinning effect where the defects can act as obstacles for the free movement of dislocation lines. And the evolution of the defects' size and number density could be responsible for the saturation of hardness. - Highlights: •Irradiation Swelling: The irradiation induced volumetric swelling increases with ion dose. •Irradiation Hardening: The irradiation hardening initiates below 1 dpa, then saturates with higher ion dose (1–10 dpa). •Irradiation Mechanism: The irradiation phenomena are ascribed to the microstructural evolution of the irradiation defects.

N-stearoylethanolamine restores pancreas lipid composition in obesity-induced insulin resistant rats.

Science.gov (United States)

Onopchenko, Oleksandra V; Kosiakova, Galina V; Oz, Murat; Klimashevsky, Vitaliy M; Gula, Nadiya M

2015-01-01

This study investigates the protective effect of N-stearoylethanolamine (NSE), a bioactive N-acylethanolamine , on the lipid profile distribution in the pancreas of obesity-induced insulin resistant (IR) rats fed with prolonged high fat diet (58% of fat for 6 months). The phospholipid composition was determined using 2D thin-layer chromatography. The level of individual phospholipids was estimated by measuring inorganic phosphorus content. The fatty acid (FA) composition and cholesterol level were investigated by gas-liquid chromatography. Compared to controls, plasma levels of triglycerides and insulin were significantly increased in IR rats. The pancreas lipid composition indicated a significant reduction of the free cholesterol level and some phospholipids such as phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylinositol (PtdIns), phosphatidylserine (PtdSer) compared to controls. Moreover, the FA composition of pancreas showed a significant redistribution of the main FA (18:1n-9, 18:2n-6, 18:3n-6 and 20:4n-6) levels between phospholipid, free FA, triglyceride fractions under IR conditions that was accompanied by a change in the estimated activities of Δ9-, Δ6-, Δ5-desaturase. Administration of N-stearoylethanolamine (NSE, 50 mg/kg daily per os for 2 weeks) IR rats triggered an increase in the content of free cholesterol, PtdCho and normalization of PtdEtn, PtdSer level. Furthermore, the NSE modulated the activity of desaturases, thus influenced FA composition and restored the FA ratios in the lipid fractions. These NSE-induced changes were associated with a normalization of plasma triglyceride content, considerable decrease of insulin and index HOMA-IR level in rats under IR conditions.

Cell Fate of Müller Cells During Photoreceptor Regeneration in an N-Methyl-N-nitrosourea-Induced Retinal Degeneration Model of Zebrafish.

Science.gov (United States)

Ogai, Kazuhiro; Hisano, Suguru; Sugitani, Kayo; Koriyama, Yoshiki; Kato, Satoru

2016-01-01

Zebrafish can regenerate several organs such as the tail fin, heart, central nervous system, and photoreceptors. Very recently, a study has demonstrated the photoreceptor regeneration in the alkylating agent N-methyl-N-nitrosourea (MNU)-induced retinal degeneration (RD) zebrafish model, in which whole photoreceptors are lost within a week after MNU treatment and then regenerated within a month. The research has also shown massive proliferation of Müller cells within a week. To address the question of whether proliferating Müller cells are the source of regenerating photoreceptors, which remains unknown in the MNU-induced zebrafish RD model, we employed a BrdU pulse-chase technique to label the proliferating cells within a week after MNU treatment. As a result of the BrdU pulse-chase technique, a number of BrdU(+) cells were observed in the outer nuclear layer as well as the inner nuclear layer. This implies that regenerating photoreceptors are derived from proliferating Müller cells in the zebrafish MNU-induced RD model.

Preventive effect of Oenothera rosea on N-methyl-N-nitrosourea-(NMU) induced gastric cancer in rats.

Science.gov (United States)

Almora-Pinedo, Yuan; Arroyo-Acevedo, Jorge; Herrera-Calderon, Oscar; Chumpitaz-Cerrate, Víctor; Hañari-Quispe, Renán; Tinco-Jayo, Aldo; Franco-Quino, Cesar; Figueroa-Salvador, Linder

2017-01-01

Currently, gastric cancer (GC) is considered a public health problem worldwide. Using medicinal plants for the prevention of chronic diseases such as cancer constitutes new alternatives in traditional medicine. Oenothera rosea (OR) could be an option, but it needs to be evaluated. The main objective of this study was to evaluate the protective effect of OR extract on N-methyl-N-nitrosourea (NMU)-induced GC in rats. In total, 80 male Holtzman rats were randomized into five groups. Group A received the saline solution (5mL/kg), group B received NMU 500 μg/kg (cancer inductor) by oral administration for 16 weeks, and groups C, D, and E were treated with OR extract (100, 200, and 300 mg/kg, respectively) and NMU in order to evaluate the preventive effect on cancer induced by NMU for 16 weeks. Blood and histological samples of stomachs were collected to determine histopathological, biochemical, and hematological parameters between different experimental groups. Groups C, D, and E presented less histopathological changes such as anaplastic and hyperplastic cells, compared with group B. Hematological and biochemical parameters were recorded, and superoxide dismutase, malondialdehyde, and nitric oxide levels were statistically less than those of NMU group ( P <0.05, P <0.01, and P <0.01). Considering the histopathological signs and the antioxidant activity in vivo as well as hematological and biochemical parameters of ethanolic extract of OR, we concluded that its administration in rats has a protective effect on GC, which is induced experimentally. This species could be studied in clinical trials for patients with GC in the future.

The effect of N-acetylcysteine on cardiac contractility to dobutamine in rats with streptozotocin-induced diabetes.

Science.gov (United States)

Cheng, Xing; Xia, Zhengyuan; Leo, Joyce M; Pang, Catherine C Y

2005-09-05

We examined if myocardial depression at the acute phase of diabetes (3 weeks after injection of streptozotocin, 60 mg/kg i.v.) is due to activation of inducible nitric oxide synthase and production of peroxynitrite, and if treatment with N-acetylcysteine (1.2 g/day/kg for 3 weeks, antioxidant) improves cardiac function. Four groups of rats were used: control, N-acetylcysteine-treated control, diabetic and N-acetylcysteine-treated diabetic. Pentobarbital-anaesthetized diabetic rats, relative to the controls, had reduced left ventricular contractility to dobutamine (1-57 microg/min/kg). The diabetic rats also had increased myocardial levels of thiobarbituric acid reactive substances, immunostaining of inducible nitric oxide synthase and nitrotyrosine, and similar baseline 15-F2t-isoprostane. N-acetylcysteine did not affect responses in the control rats; but increased cardiac contractility to dobutamine, reduced myocardial immunostaining of inducible nitric oxide synthase and nitrotyrosine and level of 15-F2t-isoprostane, and increased cardiac contractility to dobutamine in the diabetic rats. Antioxidant supplementation in diabetes reduces oxidative stress and improves cardiac function.

Blockade of central nicotine acetylcholine receptor signaling attenuate ghrelin-induced food intake in rodents.

Science.gov (United States)

Dickson, S L; Hrabovszky, E; Hansson, C; Jerlhag, E; Alvarez-Crespo, M; Skibicka, K P; Molnar, C S; Liposits, Z; Engel, J A; Egecioglu, E

2010-12-29

Here we sought to determine whether ghrelin's central effects on food intake can be interrupted by nicotine acetylcholine receptor (nAChR) blockade. Ghrelin regulates mesolimbic dopamine neurons projecting from the ventral tegmental area (VTA) to the nucleus accumbens, partly via cholinergic VTA afferents originating in the laterodorsal tegmental area (LDTg). Given that these cholinergic projections to the VTA have been implicated in natural as well as drug-induced reinforcement, we sought to investigate the role of cholinergic signaling in ghrelin-induced food intake as well as fasting-induced food intake, for which endogenous ghrelin has been implicated. We found that i.p. treatment with the non-selective centrally active nAChR antagonist, mecamylamine decreased fasting-induced food intake in both mice and rats. Moreover, central administration of mecamylamine decreased fasting-induced food intake in rats. I.c.v. ghrelin-induced food intake was suppressed by mecamylamine i.p. but not by hexamethonium i.p., a peripheral nAChR antagonist. Furthermore, mecamylamine i.p. blocked food intake following ghrelin injection into the VTA. Expression of the ghrelin receptor, the growth hormone secretagogue receptor 1A, was found to co-localize with choline acetyltransferase, a marker of cholinergic neurons, in the LDTg. Finally, mecamylamine treatment i.p. decreased the ability of palatable food to condition a place preference. These data suggest that ghrelin-induced food intake is partly mediated via nAChRs and that nicotinic blockade decreases the rewarding properties of food. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Determinantes del retraso de la interrupción voluntaria del embarazo Determinants of induced abortion delay

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Laia Font-Ribera

2009-10-01

Full Text Available Antecedentes: El momento de la gestación en que se induce una interrupción voluntaria del embarazo (IVE determina el método, el riesgo de complicaciones y el coste económico de la intervención. El objetivo de nuestro estudio fue describir los determinantes del retraso de la IVE hasta el segundo trimestre de gestación en Barcelona. Métodos: Estudio transversal de las IVE por motivos de salud física o mental de la mujer (Barcelona, 2004-2005; N=9.175. El registro de IVE de la ciudad proporcionó el tiempo de gestación (variable dependiente, el nivel de estudios, la edad, la convivencia en pareja, el número de hijos, IVE anteriores y tipo de centro. Se calcularon razones de prevalencia ajustadas (RPa mediante modelos de regresión log-binomial. Resultados: El 7,7% de las IVE fueron de segundo trimestre y el 99,3% se realizaron en centros privados. En comparación con las mujeres con estudios universitarios, las que tienen educación primaria o menos tienen una RPa de 1,8 (intervalo de confianza del 95% [IC95%]: 1,4-2,2 de IVE de segundo trimestre. También se registran más IVE de segundo trimestre en las menores de 18 años (RPa=2,6; IC95%: 2,0-3,4, las que no conviven en pareja (RPa=1,4; IC95%: 1,2-1,6 y en los centros públicos (RPa=2,8; IC95%: 2,2-3,7. No hay diferencias en el retraso de la IVE entre las mujeres que han tenido IVE anteriores y las que no. Conclusión: El retraso de la IVE hasta el segundo trimestre se asoció a niveles educativos más bajos, edades jóvenes, no convivencia en pareja y centros públicos, y se demuestra la existencia de desigualdades socioeconómicas en las condiciones de acceso a la IVE.Background: In induced abortion, the method, the risk of complications and the economic cost of the abortion are determined by gestational age. The aim of this study was to describe the determinants of induced abortion delay until the second trimester of pregnancy in Barcelona. Methods: We performed a cross

Standard Practice for Ensuring Test Consistency in Neutron-Induced Displacement Damage of Electronic Parts

CERN Document Server

American Society for Testing and Materials. Philadelphia

2007-01-01

1.1 This practice sets forth requirements to ensure consistency in neutron-induced displacement damage testing of silicon and gallium arsenide electronic piece parts. This requires controls on facility, dosimetry, tester, and communications processes that affect the accuracy and reproducibility of these tests. It provides background information on the technical basis for the requirements and additional recommendations on neutron testing. In addition to neutrons, reactors are used to provide gamma-ray pulses of intensities and durations that are not achievable elsewhere. This practice also provides background information and recommendations on gamma-ray testing of electronics using nuclear reactors. 1.2 Methods are presented for ensuring and validating consistency in neutron displacement damage testing of electronic parts such as integrated circuits, transistors, and diodes. The issues identified and the controls set forth in this practice address the characterization and suitability of the radiation environm...

Protective effects of folic acid on DNA damage and DNA methylation levels induced by N-methyl- N'-nitro- N-nitrosoguanidine in Kazakh esophageal epithelial cells.

Science.gov (United States)

Chen, Y; Feng, H; Chen, D; Abuduwaili, K; Li, X; Zhang, H

2018-01-01

The protective effects of folic acid on DNA damage and DNA methylation induced by N-methyl- N'-nitro- N-nitrosoguanidine (MNNG) in Kazakh esophageal epithelial cells were investigated using a 3 × 3 factorial design trial. The cells were cultured in vitro and exposed to media containing different concentrations of folic acid and MNNG, after which growth indices were detected. DNA damage levels were measured using comet assays, and genome-wide DNA methylation levels (MLs) were measured using high-performance liquid chromatography. The DNA methylation of methylenetetrahydrofolate reductase (MTHFR) and folate receptor- α (FR α) genes was detected by bisulfite sequencing polymerase chain reaction (PCR). The results showed significant increases in tail DNA concentration, tail length, and Olive tail moment ( p methylation frequencies of MTHFR and FR α genes. In particular, significant differences were observed in the promoter regions of both genes ( p methylation in Kazakh esophageal epithelial cells upon MNNG exposure. Thus, sufficient folic acid levels could play a protective role against the damage induced by this compound.

Agregación de sistemas coloidales con cargas opuestas: efecto de la concentración de partículas

Directory of Open Access Journals (Sweden)

Puertas, A. M.

2000-08-01

Full Text Available In this work we present experimental results on aggregation of mesoscopic systems bearing opposite surface charges. The heteroaggregation is driven by electrostatic attraction. We have studied the effect of the relative particle concentration and of the surface potentials of both systems. The fastest reactions were observed when the discharged system was in excess, which cannot be explained by the kinetic theory usually employed.

En este trabajo se presentan resultados experimentales de agregación en sistemas mesoscópicos con cargas opuestas. La heteroagregación está controlada por la atracción electrostática. Se ha estudiado el efecto de la proporción relativa de partículas de uno u otro signo y de los potenciales superficiales de ambos sistemas. Las velocidades de agregación más rápidas se han obtenido cuando el sistema más descargado se encuentra en exceso, lo que no puede ser explicado por la teoría cinética habitualmente empleada.

Radiactividad natural de los materiales de construcción. Aplicación al hormigón. Parte II. Radiación interna: el gas radón

OpenAIRE

Piedecausa García, Beatriz; Chinchón Payá, Servando; Morales Recio, Miguel Ángel; Sanjuán Barbudo, Miguel Ángel

2011-01-01

El presente artículo analiza aspectos relacionados con los tipos de radiactividad natural presentes en el interior de las edificaciones, sus fuentes y sus influencias. Más concretamente, desarrolla el estudio de la radiactividad ambiental en el interior de los espacios construidos debida a la presencia del gas radón, así como sus fuentes de origen y los niveles recomendados. Este es un artículo que se presenta como la segunda parte de un trabajo sobre radiactividad natural en los materiales d...

Role Of Shark Cartilage In Reducing Changes In Gene Expression Of Some Enzymes Induced By N-Nitroso-N-Methyl Urea In Prostate Of Irradiated Rats

International Nuclear Information System (INIS)

ELMAGHRABY, T.; YACOUB, S.; IBRAHIM, N.K.

2009-01-01

There is overwhelming evidence to indicate that free radicals cause oxidative damage to lipids, proteins and nucleic acids and are involved in the pathogenesis of several diseases. Therefore, antioxidants, which can neutralize free radicals, may be of central importance in the prevention of these diseases. Recent studies demonstrated the role of shark cartilage in protecting cells against reactive oxygen species induced DNA damage and mutagenesis. Reactive oxygen species and other free radicals are known to be the mediators of phenotypic and genotypic changes that lead from mutation to neoplasia. There are some primary antioxidants such as glutathione peroxidase (GSHPx), glutathione-S-transferase (GST-π) and super oxide dismutase (SOD), which protects against cellular and molecular damage caused by the reactive oxygen metabolites (ROMs).In this study, the effect of shark cartilage against the N-nitroso-N-methyl urea + testosterone and/or gamma radiation-induced mutagens and carcinogens in rat prostate were investigated.The data showed significant decrease in gene expression of manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GSHPx1) , enzyme activities of total superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) and non-significant increase in glutathione-S-transferase (GST-π) in N-nitroso-N-methyl urea + testosterone, N-nitroso-N-methyl urea + testosterone + gamma radiation groups as compared to control group.The results revealed that shark cartilage administration afford a significant protective effect against N-nitroso-N-methyl urea + testosterone and/or gamma radiation- induced oxidative injury.

Joint optimisation of spare part inventory, maintenance frequency and repair capacity for k-out-of-N systems

NARCIS (Netherlands)

de Smidt-Destombes, Karin S.; van der Heijden, Matthijs C.; van Harten, Aart

2009-01-01

To achieve a high system availability at minimal costs, relevant decisions include the choice of preventive maintenance frequency, spare part inventory levels and spare part repair capacity. We develop heuristics for the joint optimisation of these variables for (a) a single k-out-of-N system under

Reacción del γ-aminopropiltrietoxisilano (γ-APS con partículas de pizarra

Directory of Open Access Journals (Sweden)

Rodríguez, M. A.

2001-04-01

Full Text Available Silane Coupling Agents (SCA are widely used in fibers or particulates reinforced polymer composites to provide a water resistant bond between these reinforcements and the polymer martix. Many methods have been employed to study the interaction of SCA with inorganic surfaces in order to understand if a covalent bonding at the particulates and silane interface exists. In this work it has been used Fourier Transform infrared (FT-IR spectroscopy, differential thermal analysis (DTA-TG and specific surface área analysis in order to study the reaction of γ-aminopropiltrietoxisilane (γ-APS with slate particulates and to know the surfaces changes occurring after treatment.

Los agentes de acoplamiento silanos son frecuentemente utilizados para modificar superficies de fibras o partículas utilizadas como refuerzo en composites de matriz orgánica. Para comprobar la formación de enlaces resistentes entre los agentes de acoplamiento y las partículas inorgánicas se han empleado muchos métodos experimentales. En este trabajo se ha utilizado la espectroscopía infrarroja por transformadas de Fourier (FT-IR, el análisis térmico diferencial y termogravimétrico (ATD-TG y el análisis de la superficie específica como métodos para estudiar la reacción del agente de acoplamiento γ-aminopropiltrietoxisilano (γ-APS con partículas de pizarra y poder conocer la modificación que ha sufrido la superficie después del tratamiento.

Sedimentación de partículas con distribución de tamaño fractal Sedimentation of fractal size distribution particles

Directory of Open Access Journals (Sweden)

Roberto R. Filgueira

2006-06-01

Full Text Available Desde hace varios años, el modelo de fragmentación fractal ha atraido la atención de los investigadores, como un camino lógico para describir e interpretar distribuciones de partículas observadas. El análisis textural de un suelo ha mostrado ser muy importante, pues se utiliza para diagnosticar y predecir el funcionamiento y uso del mismo. Los métodos más populares para determinar la textura han sido los de sedimentación en agua utilizando el hidrómetro o la pipeta. Ambos tienen como objetivo encontrar la fracción de masa de partículas que se encuentran en suspensión a tiempos prefijados y relacionarla con los diámetros de las mismas. En este trabajo se ha desarrollado una nueva función potencial que relaciona la fracción de masa en suspensión con el tiempo de sedimentación. Utilizando la misma se puede determinar la dimensión fractal de fragmentación de una distribución de partículas en sedimentación. La nueva ecuación ha sido chequeada con datos propios obtenidos por el hidrómetro de Bouyoucos y otros publicados en la literatura, obtenidos mediante la pipeta de Robinson. El acuerdo logrado entre la teoría y los datos experimentales, mediante la técnica de regresión no lineal, ha sido excelente. Los valores de la dimensión fractal de fragmentación resultaron entre 2,404 y 2,512, para muestras de La Plata, Argentina, y entre 2,434 y 2,819 para los suelos de California, USA. El coeficiente de determinación, R², fue en todos los casos mayor que 0,9.Since several years the fractal fragmentation model has attracted the attention of researchers, as a logic way to describe and interprete observed particle size distributions. Textural analysis has shown to be very important because of its usefulness in the dignosis and inferences about soil functioning and use. Most popular methods of textural analysis employ sedimentation of particles in water using the hydrometer or the pipet. Both have the objective of determining the

Peritoneal fluid modulates the sperm acrosomal exocytosis induced by N-acetylglucosaminyl neoglycoprotein

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E.P. Passos

1999-01-01

Full Text Available The effect of peritoneal fluid (PF on the human sperm acrosome reaction (AR was tested. Sperm was pre-incubated with PF and the AR was induced by calcium ionophore A23187 and a neoglycoprotein bearing N-acetylglycosamine residues (NGP. The AR induced by calcium ionophore was inhibited 40% by PF from controls (PFc and 50% by PF from the endometriosis (PFe group, but not by PF from infertile patients without endometriosis (PFi. No significant differences were found in the spontaneous AR. When the AR was induced by NGP, pre-incubation with PFc reduced (60% the percentage of AR, while PFe and PFi caused no significant differences. The average rates of acrosome reactions obtained in control, NGP- and ionophore-treated sperm showed that NGP-induced exocytosis differed significantly between the PFc (11% and PFe/PFi groups (17%, and the ionophore-induced AR was higher for PFi (33% than PFc/PFe (25%. The incidence of the NGP-induced AR was reduced in the first hour of pre-incubation with PFc and remained nearly constant throughout 4 h of incubation. The present data indicate that PF possesses a protective factor which prevents premature AR.

N-Acetyl Cysteine Protects against Methamphetamine-Induced Dopaminergic Neurodegeneration via Modulation of Redox Status and Autophagy in Dopaminergic Cells

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Prashanth Chandramani Shivalingappa

2012-01-01

Full Text Available Methamphetamine- (MA- induced neurotoxicity is associated with mitochondrial dysfunction and enhanced oxidative stress. Our previous study demonstrated that MA induces autophagy in a dopaminergic neuronal cell model (N27 cells. The cellular mechanisms underlying MA-induced autophagy and apoptosis remain poorly characterized. In the present study we sought to investigate the importance of GSH redox status in MA-induced neurotoxicity using a thiol antioxidant, N-acetylcysteine (NAC. Morphological and biochemical analysis revealed that MA-induced autophagy in N27 dopaminergic cells was associated with pronounced depletion of GSH levels. Moreover, pretreatment with NAC reduced MA-induced GSH depletion and autophagy, while depletion of GSH using L-buthionine sulfoximine (L-BSO enhanced autophagy. Furthermore, treatment with NAC significantly attenuated MA-induced apoptotic cell death as well as oxidative stress markers, namely, 3-nitrotyrosine (3-NT and 4-hydroxynonenal (4-HNE. Together, these results suggest that NAC exhibits significant protective effects against MA-induced dopaminergic cell death, presumably via modulation of the GSH level and autophagy. Collectively, our data provide mechanistic insights into the role of cellular GSH redox status in MA-induced autophagy and apoptotic cell death, and additional studies are needed to determine the therapeutic effectiveness of cellular redox modifiers in attenuating dopaminergic neurodegeneration in vivo.

Ar plasma induced deep levels in epitaxial n-GaAs

International Nuclear Information System (INIS)

Venter, A.; Nyamhere, C.; Botha, J. R.; Auret, F. D.; Janse van Rensburg, P. J.; Meyer, W. E.; Coelho, S. M. M.; Kolkovsky, V. l.

2012-01-01

Ar plasma etching of n-type (Si doped) GaAs introduces several electron traps (E c - 0.04 eV, E c - 0.07 eV, E c - 0.19 eV, E c - 0.31 eV, E c - 0.53 eV, and E c - 0.61 eV). The trap, E c - 0.04 eV, labelled E1' and having a trap signature similar to irradiation induced defect E1, appears to be metastable. E c - 0.31 eV and E c - 0.61 eV are metastable too and they are similar to the M3/M4 defect configuration present in hydrogen plasma exposed n-GaAs.

Cracking of GaN on sapphire from etch-process-induced nonuniformity in residual thermal stress

International Nuclear Information System (INIS)

Lacroix, Yves; Chung, Sung-Hoon; Sakai, Shiro

2001-01-01

An experiment was performed to explain the appearance of cracks along mesa structures during the processing of GaN device layers grown on sapphire substrates. Micro-Raman spectroscopy was used to measure the position-dependent stress in the GaN layer. We show evidence that the stress at the interface with the substrate may be larger along the mesa structures than that of the as-grown layer, and that this increase in stress can be enough to induce cracks along mesa structures during processing. We report on the formation of cracks that propagate guided by the nonuniformity of the stress induced by the formation of mesa structures in the GaN layer, independent of crystal direction. The understanding of cracking mechanisms has implications in GaN-based device structures that require heteroepitaxial growth of layers with different lattice size and thermal expansion coefficients. [copyright] 2001 American Institute of Physics

Root-induced decomposer growth and plant N uptake are not positively associated among a set of grassland plants

DEFF Research Database (Denmark)

Saj, S.; Mikola, J.; Ekelund, Flemming

2008-01-01

It is known that plant species can induce development of different soil decomposer communities and that they differ in their influence on organic matter decomposition and N mineralization in soil. However, no study has so far assessed whether these two observations are related to each other. Base...... that plant traits such as competitive ability for soil mineral N were more important for plant uptake of litter-N than those that directly affected the growth of soil decomposers.......It is known that plant species can induce development of different soil decomposer communities and that they differ in their influence on organic matter decomposition and N mineralization in soil. However, no study has so far assessed whether these two observations are related to each other. Based...... on the hypothesis that root-induced growth of soil decomposers leads to accelerated decomposition of SOM and increased plant N availability in soil, we predicted that (1) among a set of grassland plants the abundance of soil decomposers in the plant rhizosphere is positively associated with plant N uptake from soil...

Crónica de una restitución : La devolución de restos como parte del reconocimiento del genocidio Selk´man

OpenAIRE

Badenes, Daniel

2016-01-01

El 19 de abril se concretó en el Museo de La Plata una acción reparatoria para la comunidad Selk´nam: la restitución de los restos humanos de cuatro integrantes de esa etnia -sólo uno de ellos identificado con nombre-, que hasta ese día fueron parte de la extensa colección que la institución formó a partir de las campañas de exterminio contra los pueblos originarios desarrolladas por el Estado argentino en el último cuarto del siglo XIX. Tras la firma de actas entre las autoridades ...

Evaluation for dinitrogen fixation of induced wheat nodules by 15N isotope dilution method

International Nuclear Information System (INIS)

Yao Yunyin; Zhen Ming; Chang Xizhong

1993-11-01

The results in pot experiments showed that the treating of 2,4-D and Azorhizobium caulinodans (2,4-D+A) could induce para-nodule formation on wheat roots. Plants treated grew normally. The plant height and dry weight are significantly higher than reference plants which are treated with 2,4-D+azorhizobium sterilized (2,4-D+AS). The nitrogenase activity is detected by ARA method. The N yield of most treated plants, especially in root systems, is higher than reference group that is measured by Kjeldahl method. The atom % 15 N excess in leaf and stem of treated plants measured by 15 N isotope dilution method is lower than that of reference group. Through four years experiments, it shows that para-nodules of wheat treated with 2,4-D+A could fix N 2 from air, but the ability of nitrogen fixation is lower and unstable. Although the nodulation efficiency could reach 100%, not each para-nodule induced can present activity of dinitrogen fixation. The amount of N fixed is 0.05∼18.1 mg/pot (0.01∼3.87 mg/plant). The net %Ndfa is 2.32%∼18.07%. The free-living N 2 fixing activity of azorhizobium is detected by 15 N isotope dilution method. The calculation of %Ndfa of nodulated wheat accurately is also discussed

Involvement of H- and N-Ras isoforms in transforming growth factor-β1-induced proliferation and in collagen and fibronectin synthesis

International Nuclear Information System (INIS)

Martinez-Salgado, Carlos; Fuentes-Calvo, Isabel; Garcia-Cenador, Begona; Santos, Eugenio; Lopez-Novoa, Jose M.

2006-01-01

Transforming growth factor β1 (TGF-β1) has a relevant role in the origin and maintenance of glomerulosclerosis and tubule-interstitial fibrosis. TGF-β and Ras signaling pathways are closely related: TGF-β1 overcomes Ras mitogenic effects and Ras counteracts TGF-β signaling. Tubule-interstitial fibrosis is associated to increases in Ras, Erk, and Akt activation in a renal fibrosis model. We study the role of N- and H-Ras isoforms, and the involvement of the Ras effectors Erk and Akt, in TGF-β1-mediated extracellular matrix (ECM) synthesis and proliferation, using embrionary fibroblasts from double knockout (KO) mice for H- and N-Ras (H-ras -/- /N-ras -/- ) isoforms and from heterozygote mice (H-ras +/- /N-ras +/- ). ECM synthesis is increased in basal conditions in H-ras -/- /N-ras -/- fibroblasts, this increase being higher after stimulation with TGF-β1. TGF-β1-induced fibroblast proliferation is smaller in H-ras -/- /N-ras -/- than in H-ras +/- /N-ras +/- fibroblasts. Erk activation is decreased in H-ras -/- /N-ras -/- fibroblasts; inhibition of Erk activation reduces fibroblast proliferation. Akt activation is higher in double KO fibroblasts than in heterozygotes; inhibition of Akt activation also inhibits ECM synthesis. We suggest that H- and N-Ras isoforms downregulate ECM synthesis, and mediate proliferation, in part through MEK/Erk activation. PI3K-Akt pathway activation may be involved in the increase in ECM synthesis observed in the absence of H- and N-Ras

N-acetylcysteine protects against cadmium-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in testes.

Science.gov (United States)

Ji, Yan-Li; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Xu, De-Xiang

2013-03-01

Cadmium (Cd) is a reproductive toxicant that induces germ cell apoptosis in the testes. Previous studies have demonstrated that endoplasmic reticulum (ER) stress is involved in Cd-induced germ cell apoptosis. The aim of the present study was to investigate the effects of N-acetylcysteine (NAC), an antioxidant, on Cd-induced ER stress and germ cell apoptosis in the testes. Male CD-1 mice were intraperitoneally injected with CdCl2 (2.0 mg kg(-1)). As expected, acute Cd exposure induced germ cell apoptosis in the testes, as determined by terminal dUTP nick-end labelling (TUNEL). However, the administration of NAC alleviated Cd-induced germ cell apoptosis in the testes. Further analysis showed that NAC attenuated the Cd-induced upregulation of testicular glucose-regulated protein 78 (GRP78), an important ER molecular chaperone. Moreover, NAC inhibited the Cd-induced phosphorylation of testicular eukaryotic translation initiation factor 2α (eIF2α), a downstream target of the double-stranded RNA-activated kinase-like ER kinase (PERK) pathway. In addition, NAC blocked the Cd-induced activation of testicular X binding protein (XBP)-1, indicating that NAC attenuates the Cd-induced ER stress and the unfolded protein response (UPR). Interestingly, NAC almost completely prevented the Cd-induced elevation of C/EBP homologous protein (CHOP) and phosphorylation of c-Jun N-terminal kinase (JNK), two components of the ER stress-mediated apoptotic pathway. In conclusion, NAC protects against Cd-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in the testes.

Defect-impurity complex induced long-range ferromagnetism in GaN nanowires

KAUST Repository

Assa Aravindh, S

2015-12-14

Present work investigates the structural, electronic and magnetic properties of Gd doped wurtzite GaN nanowires (NWs) oriented along the [0001] direction in presence of intrinsic defects by employing the GGA + U approximation. We find that Ga vacancy (VGa) exhibits lower formation energy compared to N vacancy. Further stabilization of point defects occurs due to the presence of Gd. The strength of ferromagnetism (FM) increases by additional positive charge induced by the VGa. Electronic structure analysis shows that VGa introduces defect levels in the band gap leading to ferromagnetic coupling due to the hybridization of the p states of the Ga and N atoms with the Gd d and f states. Ferromagnetic exchange coupling energy of 76.4 meV is obtained in presence of Gd-VGa complex; hence, the FM is largely determined by the cation vacancy-rare earth complex defects in GaN NWs.

Defect-impurity complex induced long-range ferromagnetism in GaN nanowires

KAUST Repository

Assa Aravindh, S; Roqan, Iman S.

2015-01-01

Present work investigates the structural, electronic and magnetic properties of Gd doped wurtzite GaN nanowires (NWs) oriented along the [0001] direction in presence of intrinsic defects by employing the GGA + U approximation. We find that Ga vacancy (VGa) exhibits lower formation energy compared to N vacancy. Further stabilization of point defects occurs due to the presence of Gd. The strength of ferromagnetism (FM) increases by additional positive charge induced by the VGa. Electronic structure analysis shows that VGa introduces defect levels in the band gap leading to ferromagnetic coupling due to the hybridization of the p states of the Ga and N atoms with the Gd d and f states. Ferromagnetic exchange coupling energy of 76.4 meV is obtained in presence of Gd-VGa complex; hence, the FM is largely determined by the cation vacancy-rare earth complex defects in GaN NWs.

Reciprocal activation of α5-nAChR and STAT3 in nicotine-induced human lung cancer cell proliferation.

Science.gov (United States)

Zhang, Yao; Jia, Yanfei; Li, Ping; Li, Huanjie; Xiao, Dongjie; Wang, Yunshan; Ma, Xiaoli

2017-07-20

Cigarette smoking is the top environmental risk factor for lung cancer. Nicotine, the addictive component of cigarettes, induces lung cancer cell proliferation, invasion and migration via the activation of nicotinic acetylcholine receptors (nAChRs). Genome-wide association studies (GWAS) show that CHRNA5 gene encoding α5-nAChR is especially relevant to lung cancer. However, the mechanism of this subunit in lung cancer is not clear. In the present study, we demonstrate that the expression of α5-nAChR is correlated with phosphorylated STAT3 (pSTAT3) expression, smoking history and lower survival of non-small cell lung cancer (NSCLC) samples. Nicotine increased the levels of α5-nAChR mRNA and protein in NSCLC cell lines and activated the JAK2/STAT3 signaling cascade. Nicotine-induced activation of JAK2/STAT3 signaling was inhibited by the silencing of α5-nAChR. Characterization of the CHRNA5 promoter revealed four STAT3-response elements. ChIP assays confirmed that the CHRNA5 promoter contains STAT3 binding sites. By silencing STAT3 expression, nicotine-induced upregulation of α5-nAChR was suppressed. Downregulation of α5-nAChR and/or STAT3 expression inhibited nicotine-induced lung cancer cell proliferation. These results suggest that there is a feedback loop between α5-nAChR and STAT3 that contributes to the nicotine-induced tumor cell proliferation, which indicates that α5-nAChR is an important therapeutic target involved in tobacco-associated lung carcinogenesis. Copyright © 2017 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

Vγ4+γδT Cells Aggravate Severe H1N1 Influenza Virus Infection-Induced Acute Pulmonary Immunopathological Injury via Secreting Interleukin-17A

Directory of Open Access Journals (Sweden)

Chunxue Xue

2017-08-01

Full Text Available The influenza A (H1N1 pdm09 virus remains a critical global health concern and causes high levels of morbidity and mortality. Severe acute lung injury (ALI and acute respiratory distress syndrome (ARDS are the major outcomes among severely infected patients. Our previous study found that interleukin (IL-17A production by humans or mice infected with influenza A (H1N1 pdm09 substantially contributes to ALI and subsequent morbidity and mortality. However, the cell types responsible for IL-17A production during the early stage of severe influenza A (H1N1 pdm09 infection remained unknown. In this study, a mouse model of severe influenza A (H1N1 pdm09 infection was established. Our results show that, in the lungs of infected mice, the percentage of γδT cells, but not the percentages of CD4+Th and CD8+Tc cells, gradually increased and peaked at 3 days post-infection (dpi. Further analysis revealed that the Vγ4+γδT subset, but not the Vγ1+γδT subset, was significantly increased among the γδT cells. At 3 dpi, the virus induced significant increases in IL-17A in the bronchoalveolar lavage fluid (BALF and serum. IL-17A was predominantly secreted by γδT cells (especially the Vγ4+γδT subset, but not CD4+Th and CD8+Tc cells at the early stage of infection, and IL-1β and/or IL-23 were sufficient to induce IL-17A production by γδT cells. In addition to secreting IL-17A, γδT cells secreted interferon (IFN-γ and expressed both an activation-associated molecule, natural killer group 2, member D (NKG2D, and an apoptosis-associated molecule, FasL. Depletion of γδT cells or the Vγ4+γδT subset significantly rescued the virus-induced weight loss and improved the survival rate by decreasing IL-17A secretion and reducing immunopathological injury. This study demonstrated that, by secreting IL-17A, lung Vγ4+γδT cells, at least, in part mediated influenza A (H1N1 pdm09-induced immunopathological injury. This mechanism might serve as a

Interacción piedra-ambiente, 1ª parte: formas de alteración desarrolladas sobre la piedra de la catedral de Burgos

Directory of Open Access Journals (Sweden)

Alonso, F. J.

1994-10-01

Full Text Available The description and inventory of the main alteration forms developed on Hontoria limestone, used in Burgos Cathedral, are carried out in this article. An exhaustive graphic information of these forms, as well as their location in the different parts of the building, are provided. The mapping of defects, made on façade upright projections, has been stored in a computer and digitalized. Relationships among different alterological aspects have been established from these digital images: percentages representing each type of defect on the total surface, types of deterioration more frequent in the walls, etc. The forms of deterioration are grouped in zones that, owing to their chromatic characteristics, are easy to locate in the monument, even without a nearby and detailed inspection. The aim of this procedure is to facilitate to architects and restorators useful and precise data for conservation interventions.

Se realiza la descripción e inventario de las principales formas de alteración desarrolladas sobre la caliza de Hontoria, empleada en la construcción de la Catedral de Burgos, aportando una exhaustiva información gráfica de las mismas, así como de su localización en las distintas partes del edificio. La cartografía de las lesiones, realizada sobre el alzado de las fachadas, ha sido almacenada en soporte informático. A partir de estas imágenes digitales se han establecido relaciones entre distintos aspectos alterológicos tales como: porcentaje que representa cada tipo de lesión en el total de una superficie, formas de alteración más frecuentes en los distintos paramentos, etc. Las diferentes formas de alteración se agrupan en zonas que, por sus características cromáticas, son fáciles de localizar en el monumento, sin necesidad de realizar una observación cercana y minuciosa. La finalidad de este procedimiento es facilitar a arquitectos y restauradores datos precisos y útiles para las intervenciones de

Léxico y variación : las denominaciones de las partes del ojo

OpenAIRE

Julià Luna, Carolina

2007-01-01

En el presente trabajo de investigación se analizan las características etimológicas, semánticas y dialectales del léxico de las partes del ojo a partir de las informaciones léxicas que atesoran los atlas lingüísticos del español, catalán y gallego elaborados en la Península Ibérica. Se estudian individualmente las diferentes designaciones que en las distintas zonas lingüísticas de la Península se recogen en los mapas de cinco conceptos referidos al ojo (la ‘ceja', el ‘párpado', la ‘pestaña',...

Solar-blind AlxGa1-xN/AlN/SiC photodiodes with a polarization-induced electron filter

Science.gov (United States)

Rodak, L. E.; Sampath, A. V.; Gallinat, C. S.; Chen, Y.; Zhou, Q.; Campbell, J. C.; Shen, H.; Wraback, M.

2013-08-01

Heterogeneous n-III-nitride/i-p silicon carbide (SiC) photodetectors have been demonstrated that enable the tailoring of the spectral response in the solar blind region below 280 nm. The negative polarization induced charge at the aluminum gallium nitride (AlxGa1-xN)/aluminum nitride (AlN) interface in conjunction with the positive polarization charge at the AlN/SiC interface creates a large barrier to carrier transport across the interface that results in the selective collection of electrons photoexcited to the Γ and L valleys of SiC while blocking the transport of electrons generated in the M valley. In addition, the AlxGa1-xN alloys act as transparent windows that enhance the collection of carriers generated by high energy photons in the fully depleted SiC absorption regions. These two factors combine to create a peak external quantum efficiency of 76% at 242 nm, along with a strong suppression of the long-wavelength response from 260 nm to 380 nm.

N-(1-Pyrenyl Maleimide Induces Bak Oligomerization and Mitochondrial Dysfunction in Jurkat Cells

Directory of Open Access Journals (Sweden)

Pei-Rong Huang

2015-01-01

Full Text Available N-(1-pyrenyl maleimide (NPM is a fluorescent reagent that is frequently used as a derivatization agent for the detection of thio-containing compounds. NPM has been shown to display a great differential cytotoxicity against hematopoietic cancer cells. In this study, the molecular mechanism by which NPM induces apoptosis was examined. Here, we show that treatment of Jurkat cells with NPM leads to Bak oligomerization, loss of mitochondrial membrane potential (Δψm, and release of cytochrome C from mitochondria to cytosol. Induction of Bak oligomerization appears to play a critical role in NPM-induced apoptosis, as downregulation of Bak by shRNA significantly prevented NPM-induced apoptosis. Inhibition of caspase 8 by Z-IETD-FMK and/or depletion of Bid did not affect NPM-induced oligomerization of Bak. Taken together, these results suggest that NPM-induced apoptosis is mediated through a pathway that is independent of caspase-8 activation.

10 CFR Appendix N to Part 52 - Standardization of Nuclear Power Plant Designs: Combined Licenses To Construct and Operate...

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Standardization of Nuclear Power Plant Designs: Combined Licenses To Construct and Operate Nuclear Power Reactors of Identical Design at Multiple Sites N Appendix N... FOR NUCLEAR POWER PLANTS Pt. 52, App. N Appendix N to Part 52—Standardization of Nuclear Power Plant...

Ar plasma induced deep levels in epitaxial n-GaAs

Energy Technology Data Exchange (ETDEWEB)

Venter, A.; Nyamhere, C.; Botha, J. R. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Auret, F. D.; Janse van Rensburg, P. J.; Meyer, W. E.; Coelho, S. M. M. [Department of Physics, University of the Pretoria, Lynnwood Road, Pretoria 0002 (South Africa); Kolkovsky, V. l. [Technische Universitaet, Dresden, 01062 Dresden (Germany)

2012-01-01

Ar plasma etching of n-type (Si doped) GaAs introduces several electron traps (E{sub c} - 0.04 eV, E{sub c} - 0.07 eV, E{sub c} - 0.19 eV, E{sub c} - 0.31 eV, E{sub c} - 0.53 eV, and E{sub c} - 0.61 eV). The trap, E{sub c} - 0.04 eV, labelled E1' and having a trap signature similar to irradiation induced defect E1, appears to be metastable. E{sub c} - 0.31 eV and E{sub c} - 0.61 eV are metastable too and they are similar to the M3/M4 defect configuration present in hydrogen plasma exposed n-GaAs.

N+ ion-implantation-induced defects in ZnO studied with a slow positron beam

International Nuclear Information System (INIS)

Chen, Z Q; Sekiguchi, T; Yuan, X L; Maekawa, M; Kawasuso, A

2004-01-01

Undoped ZnO single crystals were implanted with multiple-energy N + ions ranging from 50 to 380 keV with doses from 10 12 to 10 14 cm -2 . Positron annihilation measurements show that vacancy defects are introduced in the implanted layers. The concentration of the vacancy defects increases with increasing ion dose. The annealing behaviour of the defects can be divided into four stages, which correspond to the formation and recovery of large vacancy clusters and the formation and disappearance of vacancy-impurity complexes, respectively. All the implantation-induced defects are removed by annealing at 1200 deg. C. Cathodoluminescence measurements show that the ion-implantation-induced defects act as nonradiative recombination centres to suppress the ultraviolet (UV) emission. After annealing, these defects disappear gradually and the UV emission reappears, which coincides with positron annihilation measurements. Hall measurements reveal that after N + implantation, the ZnO layer still shows n-type conductivity

In induced reconstructions of Si(1 1 1) as superlattice matched epitaxial templates for InN growth

International Nuclear Information System (INIS)

Kuyyalil, Jithesh; Tangi, Malleswararao; Shivaprasad, S.M.

2013-01-01

Graphical abstract: Display Omitted Highlights: ► A novel growth method to form InN at low growth temperatures. ► Use of Si reconstruction as a growth template for group III nitrides. ► Band gap variation of InN – Moss–Burstein shift – non-parabolic conduction band for InN. ► Super lattice matching epitaxy of metal induced reconstructions with III–V unit cell. -- Abstract: Indium induced surface reconstructions of Si(1 1 1)-7 × 7 are used as templates to grow high quality InN. We grow InN on Si(1 1 1)-7 × 7, Si(1 1 1)-4 × 1-In and Si(1 1 1)-1 × 1-In reconstructed surfaces and study the quality of the films formed using complementary characterization tools. InN grown on Si(1 1 1)-1 × 1-In reconstruction shows superior film quality with lowest band-edge emission having a narrow full width at half maximum, intense and narrow 0 0 0 2 X-ray diffraction, low surface roughness and carrier concentration an order lower than other samples. We attribute the high quality of the film formed at 300 °C to the integral matching of InN and super lattice dimensions, we also study the reasons for the band gap variation of InN in the literature. Present study demonstrates the proposed Superlattice Matched Epitaxy can be a general approach to grow good quality InN at much lower growth temperature on compatible In induced reconstructions of the Si surface.

Colonia de abejas artificiales y optimización por enjambre de partículas para la estimación de parámetros de regresión no lineal

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Sergio Gerardo de los Cobos Silva

2014-04-01

Full Text Available Este trabajo presenta la comparación de los resultados de las técnicas heurísticas de ABC colonias de abejas artificiales (Artificial Bee Colony y PSO enjambres de partículas (Particle Swarm Optimization que son utilizadas para la estimación de parámetros de modelos de regresión no lineal. Los algoritmos fueron probados sobre 27 bases de datos de la colección NIST(2001, de las cuales 8 son consideradas con un alto grado de dificultad, 11 con un grado de dificultad medio y 8 con un grado de dificultad bajo. Se presentan los resultados experimentales.

Excimer-laser-induced activation of Mg-doped GaN layers

International Nuclear Information System (INIS)

Lin, Y.-J.; Liu, W.-F.; Lee, C.-T.

2004-01-01

In this study, we investigated the 248 nm excimer-laser-induced activation of the Mg-doped GaN layers. According to the observed photoluminescence results and the x-ray photoelectron spectroscopy measurements, we found that the dissociation of the Mg-H complexes and the formation of hydrogenated Ga vacancies (i.e., V Ga H 2 ) and/or the Ga vacancies occupied by interstitial Mg during the laser irradiation process, led to an increase in the hole concentration

Evaluación cualitativa en ambientes laborales con partículas suspendidas

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Mayra Islas Galicia

2015-10-01

Full Text Available El presente trabajo muestra el diseño y aplicación de una encuesta que incluye principios de ergonomía para evaluar el ambiente laboral desde la perspectiva de los trabajadores en centros donde se emiten partículas suspendidas capaces de generar contaminación. El objetivo que se persigue al realizar dicha evaluación es promover la participación de los trabajadores en la identificación de áreas de oportunidad en cuatro dimensiones: Calidad del Aire, Capacitación, Salud, y Seguridad y Bienestar. A su vez, que la encuesta sirva como herramienta complementaria a los alcances de la NOM-010-STPS-2014 que regula las condiciones de seguridad e higiene en centros de trabajo donde se emplean sustancias químicas. La metodología que se siguió para el logro de los objetivos de este trabajo, incluyó:1 La revisión en detalle de la Norma Oficial Mexicana NOM-010-STPS2014 y la Norma Internacional UNE EN ISO 6385:2004 “Principios ergonómicos para el diseño de sistemas de trabajo”, con la finalidad de comprender su contenido en cuanto alcances, limitaciones, y aplicación de la ergonomía; 2El diseño del instrumento de medición (encuesta, que a su vez contempló: el establecimiento de las dimensiones, la elaboración de las aseveraciones y formato de respuesta, y la aplicación de la encuesta;3 Los cálculos para la obtención de resultados. La encuesta diseñada se aplicó en empresas de diferente giro, que estuvieran dentro del campo de cobertura de la NOM-010-STPS-2014; los resultados se presentan a través de un modelo gráfico que evalúa la Importancia y Desempeño, a partir de los cuales se puede destacar la necesidad de efectuar mejoras a las condiciones de trabajo y algunas cuestiones de carácter administrativo.

Evaluación cualitativa en ambientes laborales con partículas suspendidas

Directory of Open Access Journals (Sweden)

Mayra Islas Galicia

2015-11-01

Full Text Available El presente trabajo muestra el diseño y aplicación de una encuesta que incluye principios de ergonomía para evaluar el ambiente laboral desde la perspectiva de los trabajadores en centros donde se emiten partículas suspendidas capaces de generar contaminación. El objetivo que se persigue al realizar dicha evaluación es promover la participación de los trabajadores en la identificación de áreas de oportunidad en cuatro dimensiones: Calidad del Aire, Capacitación, Salud, y Seguridad y Bienestar. A su vez, que la encuesta sirva como herramienta complementaria a los alcances de la NOM-010-STPS-2014 que regula las condiciones de seguridad e higiene en centros de trabajo donde se emplean sustancias químicas. La metodología que se siguió para el logro de los objetivos de este trabajo, incluyó:1 La revisión en detalle de la Norma Oficial Mexicana NOM-010-STPS2014 y la Norma Internacional UNE EN ISO 6385:2004 “Principios ergonómicos para el diseño de sistemas de trabajo”, con la finalidad de comprender su contenido en cuanto alcances, limitaciones, y aplicación de la ergonomía; 2El diseño del instrumento de medición (encuesta, que a su vez contempló: el establecimiento de las dimensiones, la elaboración de las aseveraciones y formato de respuesta, y la aplicación de la encuesta;3 Los cálculos para la obtención de resultados. La encuesta diseñada se aplicó en empresas de diferente giro, que estuvieran dentro del campo de cobertura de la NOM-010-STPS-2014; los resultados se presentan a través de un modelo gráfico que evalúa la Importancia y Desempeño, a partir de los cuales se puede destacar la necesidad de efectuar mejoras a las condiciones de trabajo y algunas cuestiones de carácter administrativo.

GluN2C/GluN2D subunit-selective NMDA receptor potentiator CIQ reverses MK-801-induced impairment in prepulse inhibition and working memory in Y-maze test in mice

Science.gov (United States)

Suryavanshi, P S; Ugale, R R; Yilmazer-Hanke, D; Stairs, D J; Dravid, S M

2014-01-01

Background and Purpose Despite ample evidence supporting the N-methyl-d-aspartate receptor (NMDAR) hypofunction hypothesis of schizophrenia, progress in the development of effective therapeutics based on this hypothesis has been limited. Facilitation of NMDA receptor function by co-agonists (d-serine or glycine) only partially alleviates the symptoms in schizophrenia; other means to facilitate NMDA receptors are required. NMDA receptor sub-types differ in their subunit composition, with varied GluN2 subunits (GluN2A-GluN2D) imparting different physiological, biochemical and pharmacological properties. CIQ is a positive allosteric modulator that is selective for GluN2C/GluN2D-containing NMDA receptors (Mullasseril et al.). Experimental Approach The effect of systemic administration of CIQ was tested on impairment in prepulse inhibition (PPI), hyperlocomotion and stereotypy induced by i.p. administration of MK-801 and methamphetamine. The effect of CIQ was also tested on MK-801-induced impairment in working memory in Y-maze spontaneous alternation test. Key Results We found that systemic administration of CIQ (20 mg·kg−1, i.p.) in mice reversed MK-801 (0.15 mg·kg−1, i.p.)-induced, but not methamphetamine (3 mg·kg−1, i.p.)-induced, deficit in PPI. MK-801 increased the startle amplitude to pulse alone, which was not reversed by CIQ. In contrast, methamphetamine reduced the startle amplitude to pulse alone, which was reversed by CIQ. CIQ also partially attenuated MK-801- and methamphetamine-induced hyperlocomotion and stereotyped behaviours. Additionally, CIQ reversed the MK-801-induced working memory deficit in spontaneous alternation in a Y-maze. Conclusion and Implications Together, these results suggest that facilitation of GluN2C/GluN2D-containing receptors may serve as an important therapeutic strategy for treating positive and cognitive symptoms in schizophrenia. PMID:24236947

Fatty acid 16:4(n-3) stimulates a GPR120-induced signaling cascade in splenic macrophages to promote chemotherapy resistance

DEFF Research Database (Denmark)

Houthuijzen, Julia M; Oosterom, Ilse; Hudson, Brian D

2017-01-01

Although chemotherapy is designed to eradicate tumor cells, it also has significant effects on normal tissues. The platinum-induced fatty acid 16:4(n-3) (hexadeca-4,7,10,13-tetraenoic acid) induces systemic resistance to a broad range of DNA-damaging chemotherapeutics. We show that 16:4(n-3) exerts....... M., Peeper, D. S., Jafari Sadatmand, S., Roodhart, J. M. L., van de Lest, C. H. A., Ulven, T., Ishihara, K., Milligan, G., Voest, E. E. Fatty acid 16:4(n-3) stimulates a GPR120-induced signaling cascade in splenic macrophages to promote chemotherapy resistance....

Ley de Coulomb y simulación de trayectorias de partículas cargadas en campos eléctricos estacionarios

OpenAIRE

Barco Ríos, Héctor; Rojas Calderón, Edilberto

2001-01-01

Se presenta una descripción del programa de computador "Ley de Coulomb y simulación de trayectorias de partículas cargadas en campos eléctricos estacionarios" creado por el profesor H. Barco Ríos con la colaboración del profesor E. Rojas C., y que ha sido utilizado como complemento del curso de Física II que en la actualidad se desarrolla en la Universidad Nacional de Colombia Sede Manizales. Este programa hace parte de una serie de trabajos que se han venido realizando con el propósito de...

N-acetylcysteine prevents stress-induced anxiety behavior in zebrafish.

Science.gov (United States)

Mocelin, Ricieri; Herrmann, Ana P; Marcon, Matheus; Rambo, Cassiano L; Rohden, Aline; Bevilaqua, Fernanda; de Abreu, Murilo Sander; Zanatta, Leila; Elisabetsky, Elaine; Barcellos, Leonardo J G; Lara, Diogo R; Piato, Angelo L

2015-12-01

Despite the recent advances in understanding the pathophysiology of anxiety disorders, the pharmacological treatments currently available are limited in efficacy and induce serious side effects. A possible strategy to achieve clinical benefits is drug repurposing, i.e., discovery of novel applications for old drugs, bringing new treatment options to the market and to the patients who need them. N-acetylcysteine (NAC), a commonly used mucolytic and paracetamol antidote, has emerged as a promising molecule for the treatment of several neuropsychiatric disorders. The mechanism of action of this drug is complex, and involves modulation of antioxidant, inflammatory, neurotrophic and glutamate pathways. Here we evaluated the effects of NAC on behavioral parameters relevant to anxiety in zebrafish. NAC did not alter behavioral parameters in the novel tank test, prevented the anxiety-like behaviors induced by an acute stressor (net chasing), and increased the time zebrafish spent in the lit side in the light/dark test. These data may indicate that NAC presents an anti-stress effect, with the potential to prevent stress-induced psychiatric disorders such as anxiety and depression. The considerable homology between mammalian and zebrafish genomes invests the current data with translational validity for the further clinical trials needed to substantiate the use of NAC in anxiety disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

Immunomodulation of murine collagen-induced arthritis by N, N-dimethylglycine and a preparation of Perna canaliculus

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Davis Paul

2007-06-01

Full Text Available Abstract Background Rheumatoid arthritis (RA and its accepted animal model, murine collagen-induced arthritis (CIA, are classic autoimmune inflammatory diseases which require proinflammatory cytokine production for pathogenesis. We and others have previously used N, N-dimethylglycine (DMG and extracts from the New Zealand green-lipped mussel Perna canaliculus (Perna as potent immunomodulators to modify ongoing immune and/or inflammatory responses. Methods In our initial studies, we treated lipopolysaccahride (LPS stimulated THP-1 monocytes in vitro with increasing concentrations of Perna extract or DMG. Additionally, we treated rat peripheral blood neutrophils with increasing concentrations of Perna extract and measured superoxide burst. In subsequent in vivo experiments, CIA was induced by administration of type II collagen; rats were prophylactically treated with either Perna or DMG, and then followed for disease severity. Finally, to test whether Perna and/or DMG could block or inhibit an ongoing pathologic disease process, we induced CIA in mice and treated them therapeutically with either of the two immunomodulators. Results Following LPS stimulation of THP-1 monocytes, we observed dose-dependent reductions in TNF-α and IL-12p40 production in Perna treated cultures. DMG treatment, however, showed significant increases in both of these cytokines in the range of 0.001–1 μM. We also demonstrate that in vitro neutrophil superoxide burst activity is dose-dependently reduced in the presence of Perna. Significant reductions in disease incidence, onset, and severity of CIA in rats were noted following prophylactic treatment with either of the two immunomodulators. More importantly, amelioration of mouse CIA was observed following therapeutic administration of Perna. In contrast, DMG appeared to have little effect in mice and may act in a species-specific manner. Conclusion These data suggest that Perna, and perhaps DMG, may be useful

Immunomodulation of murine collagen-induced arthritis by N, N-dimethylglycine and a preparation of Perna canaliculus.

Science.gov (United States)

Lawson, Brian R; Belkowski, Stanley M; Whitesides, John F; Davis, Paul; Lawson, John W

2007-06-11

Rheumatoid arthritis (RA) and its accepted animal model, murine collagen-induced arthritis (CIA), are classic autoimmune inflammatory diseases which require proinflammatory cytokine production for pathogenesis. We and others have previously used N, N-dimethylglycine (DMG) and extracts from the New Zealand green-lipped mussel Perna canaliculus (Perna) as potent immunomodulators to modify ongoing immune and/or inflammatory responses. In our initial studies, we treated lipopolysaccahride (LPS) stimulated THP-1 monocytes in vitro with increasing concentrations of Perna extract or DMG. Additionally, we treated rat peripheral blood neutrophils with increasing concentrations of Perna extract and measured superoxide burst. In subsequent in vivo experiments, CIA was induced by administration of type II collagen; rats were prophylactically treated with either Perna or DMG, and then followed for disease severity. Finally, to test whether Perna and/or DMG could block or inhibit an ongoing pathologic disease process, we induced CIA in mice and treated them therapeutically with either of the two immunomodulators. Following LPS stimulation of THP-1 monocytes, we observed dose-dependent reductions in TNF-alpha and IL-12p40 production in Perna treated cultures. DMG treatment, however, showed significant increases in both of these cytokines in the range of 0.001-1 microM. We also demonstrate that in vitro neutrophil superoxide burst activity is dose-dependently reduced in the presence of Perna. Significant reductions in disease incidence, onset, and severity of CIA in rats were noted following prophylactic treatment with either of the two immunomodulators. More importantly, amelioration of mouse CIA was observed following therapeutic administration of Perna. In contrast, DMG appeared to have little effect in mice and may act in a species-specific manner. These data suggest that Perna, and perhaps DMG, may be useful supplements to the treatment of RA in humans.

Involvement of the N-terminal unique domain of Chk tyrosine kinase in Chk-induced tyrosine phosphorylation in the nucleus

International Nuclear Information System (INIS)

Nakayama, Yuji; Kawana, Akiko; Igarashi, Asae; Yamaguchi, Naoto

2006-01-01

Chk tyrosine kinase phosphorylates Src-family kinases and suppresses their kinase activity. We recently showed that Chk localizes to the nucleus as well as the cytoplasm and inhibits cell proliferation. In this study, we explored the role of the N-terminal unique domain of Chk in nuclear localization and Chk-induced tyrosine phosphorylation in the nucleus. In situ binding experiments showed that the N-terminal domain of Chk was associated with the nucleus and the nuclear matrix. The presence of the N-terminal domain of Chk led to a fourfold increase in cell population exhibiting Chk-induced tyrosine phosphorylation in the nucleus. Expression of Chk but not kinase-deficient Chk induced tyrosine phosphorylation of a variety of proteins ranging from 23 kDa to ∼200 kDa, especially in Triton X-100-insoluble fraction that included chromatin and the nuclear matrix. Intriguingly, in situ subnuclear fractionations revealed that Chk induced tyrosine phosphorylation of proteins that were associated with the nuclear matrix. These results suggest that various unidentified substrates of Chk, besides Src-family kinases, may be present in the nucleus. Thus, our findings indicate that the importance of the N-terminal domain to Chk-induced tyrosine phosphorylation in the nucleus, implicating that these nuclear tyrosine-phosphorylated proteins may contribute to inhibition of cell proliferation

An anthocyanin-rich extract from Hibiscus sabdariffa linnaeus inhibits N-nitrosomethylurea-induced leukemia in rats.

Science.gov (United States)

Tsai, Tsung-Chang; Huang, Hui-Pei; Chang, Yun-Ching; Wang, Chau-Jong

2014-02-19

A previous study reported that anthocyanins from roselle (Hibiscus sabdariffa L.) showed significant anticancer activity in human promyelocytic leukemia cells. To explore the antitumor effect of anthocyanin, a roselle bioactive polyphenol in a rat model of chemical-induced leukemia was assayed. Anthocyanin extract of roselle (Hibiscus anthocyanins, HAs) was supplemented in the diet (0.1 and 0.2%). This study was carried out to evaluate the protective effect of HAs on N-nitrosomethylurea (NMU)-induced leukemia of rats. The study employed male Sprague-Dawley rats (n = 48), and leukemia was induced by intravenous injection of 35 mg kg(-1) body weight of NMU dissolved in physiologic saline solution. The rats were divided into four groups (n = 12): control, NMU only, and HAs groups that received different doses of HAs (0.1 and 0.2%) daily, orally, after NMU injection. After 220 days, the animals were killed, and the following parameters were assessed: morphological observation, hematology examination, histopathological assessment, and biochemical assay. When compared with the NMU-only group, HAs significantly prevented loss of organ weight and ameliorated the impairment of morphology, hematology, and histopathology. Treatment with HAs caused reduction in the levels of AST, ALT, uric acid, and MPO. Also, the results showed that oral administration of HAs (0.2%) remarkably inhibited progression of NMU-induced leukemia by approximately 33.3% in rats. This is the first report to demonstrate that the sequential administration of HAs followed by NMU resulted in an antileukemic activity in vivo.

N-acetyl-L-tryptophan, a substance-P receptor antagonist attenuates aluminum-induced spatial memory deficit in rats.

Science.gov (United States)

Fernandes, Joylee; Mudgal, Jayesh; Rao, Chamallamudi Mallikarjuna; Arora, Devinder; Basu Mallik, Sanchari; Pai, K S R; Nampoothiri, Madhavan

2018-06-01

Neuroinflammation plays an important role in the pathophysiology of Alzheimer's disease. Neurokinin substance P is a key mediator which modulates neuroinflammation through neurokinin receptor. Involvement of substance P in Alzheimer's disease is still plausible and various controversies exist in this hypothesis. Preventing the deleterious effects of substance P using N-acetyl-L-tryptophan, a substance P antagonist could be a promising therapeutic strategy. This study was aimed to evaluate the effect of N-acetyl-L-tryptophan on aluminum induced spatial memory alterations in rats. Memory impairment was induced using aluminum chloride (AlCl 3 ) at a dose of 10 mg/kg for 42 d. After induction of dementia, rats were exposed to 30 and 50 mg/kg of N-acetyl-L-tryptophan for 28 d. Spatial memory alterations were measured using Morris water maze. Acetylcholinesterase activity and antioxidant enzyme glutathione level were assessed in hippocampus, frontal cortex and striatum. The higher dose of N-acetyl-L-tryptophan (50 mg/kg) significantly improved the aluminum induced memory alterations. N-acetyl-L-tryptophan exposure resulted in significant increase in acetylcholinesterase activity and glutathione level in hippocampus. The neuroprotective effect of N-acetyl-L-tryptophan could be due to its ability to block substance P mediated neuroinflammation, reduction in oxidative stress and anti-apoptotic properties. To conclude, N-acetyl-L-tryptophan may be considered as a novel neuroprotective therapy in Alzheimer's disease.

Canopy uptake of atmospheric N deposition at a conifer forest: part I -canopy N budget, photosynthetic efficiency and net ecosystem exchange

International Nuclear Information System (INIS)

Sievering, H.; Tomaszewski, T.; Torizzo, J.

2007-01-01

Global carbon cycle assessments of anthropogenic nitrogen (N) deposition influences on carbon sequestration often assume enhanced sequestration results. This assumption was evaluated at a Rocky Mountains spruce-fir forest. Forest canopy N uptake (CNU) of atmospheric N deposition was estimated by combining event wet and throughfall N fluxes with gradient measured HNO 3 and NH 3 as well as inferred (NO x and particulate N) dry fluxes. Approximately 80% of the growing-season 3 kg N/ha total deposition is retained in canopy foliage and branches. This CNU constitutes ∼1/3 of canopy growing season new N supply at this conifer forest site. Daytime net ecosystem exchange (NEE) significantly (P = 0.006) and negatively (CO 2 uptake) correlated with CNU. Multiple regression indicates ∼20% of daytime NEE may be attributed to CNU (P < 0.02); more than soil water content. A wet deposition N-amendment study (Tomaszewski and Sievering), at canopy spruce branches, increased their growing-season CNU by 40-50% above ambient. Fluorometry and gas exchange results show N-amended spruce branches had greater photosynthetic efficiency and higher carboxylation rates than control and untreated branches. N-amended branches had 25% less photoinhibition, with a 5-9% greater proportion of foliar-N-in-Rubisco. The combined results provide, partly, a mechanistic explanation for the NEE dependence on CNU

Effect of DNA polymerase inhibitors on DNA repair in intact and permeable human fibroblasts: Evidence that DNA polymerases δ and β are involved in DNA repair synthesis induced by N-methyl-N'-nitro-N-nitrosoguanidine

International Nuclear Information System (INIS)

Hammond, R.A.; Miller, M.R.; McClung, J.K.

1990-01-01

The involvement of DNA polymerases α, β, and δ in DNA repair synthesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was investigated in human fibroblasts (HF). The effects of anti-(DNA polymerase α) monoclonal antibody, (p-n-butylphenyl)deoxyguanosine triphosphate (BuPdGTP), dideoxythymidine triphosphate (ddTTP), and aphidicolin on MNNG-induced DNA repair synthesis were investigated to dissect the roles of the different DNA polymerases. A subcellular system (permeable cells), in which DNA repair synthesis and DNA replication were differentiated by CsCl gradient centrifugation of BrdUMP density-labeled DNA, was used to examine the effects of the polymerase inhibitors. Another approach investigated the effects of several of these inhibitors of MNNG-induced DNA repair synthesis in intact cells by measuring the amount of [ 3 H]thymidine incorporated into repair DNA as determined by autoradiography and quantitation with an automated video image analysis system. In permeable cells, MNNG-induced DNA repair synthesis was inhibited 56% by 50 μg of aphidicolin/mL, 6% by 10 μM BuPdGTP, 13% by anti-(DNA polymerse α) monoclonal antibodies, and 29% by ddTTP. In intact cells, MNNG-induced DNA repair synthesis was inhibited 57% by 50 μg of aphidicolin/mL and was not significantly inhibited by microinjecting anti-(DNA polymerase α) antibodies into HF nuclei. These results indicate that both DNA polymerase δ and β are involved in repairing DNA damage caused by MNNG

Threshold stoichiometry for beam induced nitrogen depletion of SiN

International Nuclear Information System (INIS)

Timmers, H.; Weijers, T.D.M.; Elliman, R.G.; Uribasterra, J.; Whitlow, H.J.; Sarwe, E.-L.

2002-01-01

Measurements of the stoichiometry of silicon nitride films as a function of the number of incident ions using heavy ion elastic recoil detection (ERD) show that beam-induced nitrogen depletion depends on the projectile species, the beam energy, and the initial stoichiometry. A threshold stoichiometry exists in the range 1.3>N/Si≥1, below which the films are stable against nitrogen depletion. Above this threshold, depletion is essentially linear with incident fluence. The depletion rate correlates non-linearly with the electronic energy loss of the projectile ion in the film. Sufficiently long exposure of nitrogen-rich films renders the mechanism, which prevents depletion of nitrogen-poor films, ineffective. Compromising depth-resolution, nitrogen depletion from SiN films during ERD analysis can be reduced significantly by using projectile beams with low atomic numbers

El papel de las tácticas irregulares en las guerras hibridas: la intervención en Afganistán por parte de Estados Unidos

OpenAIRE

Rojas Ibañez, Gustavo Enrique

2017-01-01

Este trabajo tiene como objetivo explicar la manera en que las tácticas irregulares son utilizadas en las guerras hibridas, tomando como ejemplo la intervención en Afganistán por parte de Estados unidos, con el fin de generalizar los principios que rigen la mayoría de los conflictos en la actualidad y poder entender las tendencias en las que se desenvolverán los combates en el futuro. Estas tácticas son utilizadas como herramienta en el combate ya que los grupos insurgentes, como los Talibán,...

Electrically active induced energy levels and metastability of B and N vacancy-complexes in 4H–SiC

Science.gov (United States)

Igumbor, E.; Olaniyan, O.; Mapasha, R. E.; Danga, H. T.; Omotoso, E.; Meyer, W. E.

2018-05-01

Electrically active induced energy levels in semiconductor devices could be beneficial to the discovery of an enhanced p or n-type semiconductor. Nitrogen (N) implanted into 4H–SiC is a high energy process that produced high defect concentrations which could be removed during dopant activation annealing. On the other hand, boron (B) substituted for silicon in SiC causes a reduction in the number of defects. This scenario leads to a decrease in the dielectric properties and induced deep donor and shallow acceptor levels. Complexes formed by the N, such as the nitrogen-vacancy centre, have been reported to play a significant role in the application of quantum bits. In this paper, results of charge states thermodynamic transition level of the N and B vacancy-complexes in 4H–SiC are presented. We explore complexes where substitutional N/N or B/B sits near a Si (V) or C (V) vacancy to form vacancy-complexes (NV, NV, NV, NV, BV, BV, BV and BV). The energies of formation of the N related vacancy-complexes showed the NV to be energetically stable close to the valence band maximum in its double positive charge state. The NV is more energetically stable in the double negative charge state close to the conduction band minimum. The NV on the other hand, induced double donor level and the NV induced a double acceptor level. For B related complexes, the BV and BV were energetically stable in their single positive charge state close to the valence band maximum. As the Fermi energy is varied across the band gap, the neutral and single negative charge states of the BV become more stable at different energy levels. B and N related complexes exhibited charge state controlled metastability behaviour.

Conceptualización de la salud ambiental: Teoría y práctica (parte 2

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Hugo Rengifo Cuéllar

2009-01-01

Full Text Available En esta segunda parte se revisa la situación de la práctica de la salud ambiental en el Perú y se proponen líneas políticas de acción tendientes a revertir los grandes problemas encontrados en este campo. Se explora cual debería ser el perfil del profesional que se desenvuelve en la salud ambiental. Se revisa cuales serían los retos a afrontar en la salud ambiental, así como algunos indicadores a tener en cuenta para la evaluación de la salud ambiental y los campos que requieren de investigación.

Aplicaciones de las Tecnologías de la Informacióny de la Comunición en la educación científica.Primera parte: funciones y recursos

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Alfonso Pontes-Pedrajas

2005-01-01

Full Text Available Las tecnologías de la información y la comunicación (TICs ejercen actualmente una influencia cada vez mayor en la educación científica, tanto en la enseñanza secundaria como en la universitaria, no sólo en lo que respecta a la mejora del aprendizaje de la ciencia por parte de los alumnos de tales niveles, sino que también desempeñan un papel creciente en la formación inicial y permanente del profesorado. Sobre esta temática hemos elaborado un trabajo de revisión, que por su extensión se ha desglosado en dos partes. En este primer artículo se realiza un análisis panorámico de tales aplicaciones, abordando las posibles funciones educativas y los tipos de recursos informáticos que pueden utilizar los profesores de ciencias experimentales

Proposed changes for part N of suggested state regulations

Energy Technology Data Exchange (ETDEWEB)

Paris, R.

1997-02-01

This paper discusses proposed changes for Part N regulations regarding naturally occuring radioactive materials. It describes the work of the Commission on NORM of the Conference of Radiation Control Program Directors (CRCPD), toward adjusting the regulations. A set of questions was formulated and a review panel established to address these questions and come back with recommended actions. The panel recommended the distinction that the material being regulated is `Technologically Enhanced Naturally Occurring Radioactive Material` (TENORM). By this they mean `naturally occurring radioactive material not regulated under the Atomic Energy Act (AEA) whose radionuclide concentrations have been increased by or as a result of human practices.` Recommendations also include: using a dose based instead of concentration based standard; refined definition of exemptions from regulations; exclusion of radon from Total Effective Dose Equivalent (TEDE) calculations; provide states flexibility in implementation; inclusion of prospective remedial and operations aspects for TENORM; provision of institutional controls.

Narrativa biográfica y motivación para el aprendizaje. ¿Por qué motivación y entendida cómo? (Segunda parte

Directory of Open Access Journals (Sweden)

Susana Inés Fernández

2014-04-01

Full Text Available El documento –primera y segunda parte- forma parte de la producción del Proyecto Nro. 1748 del CIUNSa.: “Narrativa biográfica y motivación para el aprendizaje. A la búsqueda de pistas para repensar la problemática del ingreso universitario”. Se trata de dar cuenta de las razones por las cuales se centra la indagación acerca del ingreso a la universidad en la motivación de los estudiantes y de precisar el sentido en que se entiende el término, tomando para ello diferentes fuentes bibliográficas provenientes de distintos campos disciplinares. Con esta finalidad se reseña y comenta la producción de Ana Abramowski sobre su concepto de nopodermiento escolar; se revisan los más importantes modos de intervención motivacional en el aula expuestos por Antonio Huertas y se expone la diferenciación entre motivación externa e interna desarrollada por la psicología dialéctica rusa. Se funda sobre estas conceptualizaciones, desde una perspectiva compleja del conocimiento y un enfoque socio-histórico del desarrollo psicológico humano, una definición de motivación que se conjuga con la problematización del concepto de internalización como apropiación y como dominio, tomando las ideas bajtineanas de palabra autorizada y palabra internamente persuasiva que dan lugar a la categoría de resistencia. Surge de ello el interrogante sobre los posibles efectos motivadores de la apropiación y el dominio de las formas culturales de mediación y retomando los paralelismos planteados por Abramowski entre sistema productivo y educación, se reflexiona sobre el papel de la educación en la selección de los sujetos más aptos para el sistema económico capitalista.

High mobility AlGaN/GaN heterostructures grown on Si substrates using a large lattice-mismatch induced stress control technology

International Nuclear Information System (INIS)

Cheng, Jianpeng; Yang, Xuelin; Sang, Ling; Guo, Lei; Hu, Anqi; Xu, Fujun; Tang, Ning; Wang, Xinqiang; Shen, Bo

2015-01-01

A large lattice-mismatch induced stress control technology with a low Al content AlGaN layer has been used to grow high quality GaN layers on 4-in. Si substrates. The use of this technology allows for high mobility AlGaN/GaN heterostructures with electron mobility of 2040 cm 2 /(V·s) at sheet charge density of 8.4 × 10 12  cm −2 . Strain relaxation and dislocation evolution mechanisms have been investigated. It is demonstrated that the large lattice mismatch between the low Al content AlGaN layer and AlN buffer layer could effectively promote the edge dislocation inclination with relatively large bend angles and therefore significantly reduce the dislocation density in the GaN epilayer. Our results show a great potential for fabrication of low-cost and high performance GaN-on-Si power devices

Inmunización intranasal con AFCo1 induce respuesta inmune de memoria, sistemica y mucosal en ratones neonatal

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Julio A. Balboa

2009-08-01

Full Text Available Neonates have a poorly developed immune system. Respiratory pathogens cause disease during early periods of live. Consequently, it is important to develop protective vaccines that induce immunity and immunological memory against respiratory pathogens early in life. Intranasal (i.n. route could be an effective via for immunization. Therefore, we explored the effectiveness of AF (Adjuvant Finlay PL1 (Proteoliposome from Neisseria meningitidis serogroup B and its derivate Cochleate (AFCo1 by nasal route in neonatal mice. They were immunized i.n. 3 times 7 days apart and anti PL systemic and mucosal antibody response were measured by ELISA. In addition, a prime-boost strategy was used to evaluate the humoral immune response in neonate mice. The 3 doses of AFPL1 or AFCo1 induced significant levels of anti PL IgG antibodies in comparison whit control, but AFCo1 (2017 U/mL was significantly higher than AFPL1 (1107 U/mL. AFCo1 and AFPL1 induced a predominant Th1 pattern with IgG2a/IgG1 >1 by i.n. immunization and AFCo1 induced a high anti PL IgA saliva response in saliva. Interestingly, one nasally prime at 7 days of born and a memory one boost i.n. dose 9 weeks later with AFCo1 or AFPL1 showed similar specific IgG levels and IgG2a/IgG1 relation than 3 i.n. doses in adult mice. In conclusion, these results represent the first report of neonatal intranasal vaccination using AFCo1 capable to induce systemic and mucosal immunity and priming for memory.

Auto-inducing media for uniform isotope labeling of proteins with {sup 15}N, {sup 13}C and {sup 2}H

Energy Technology Data Exchange (ETDEWEB)

Guthertz, Nicolas [Institute of Cancer Research, Division of Structural Biology (United Kingdom); Klopp, Julia; Winterhalter, Aurélie; Fernández, César; Gossert, Alvar D., E-mail: alvar.gossert@novartis.com [Novartis Institutes for BioMedical Research (Switzerland)

2015-06-15

Auto-inducing media for protein expression offer many advantages like robust reproducibility, high yields of soluble protein and much reduced workload. Here, an auto-inducing medium for uniform isotope labelling of proteins with {sup 15}N, {sup 13}C and/or {sup 2}H in E. coli is presented. So far, auto-inducing media have not found widespread application in the NMR field, because of the prohibitively high cost of labeled lactose, which is an essential ingredient of such media. Here, we propose using lactose that is only selectively labeled on the glucose moiety. It can be synthesized from inexpensive and readily available substrates: labeled glucose and unlabeled activated galactose. With this approach, uniformly isotope labeled proteins were expressed in unattended auto-inducing cultures with incorporation of {sup 13}C, {sup 15}N of 96.6 % and {sup 2}H, {sup 15}N of 98.8 %. With the present protocol, the NMR community could profit from the many advantages that auto-inducing media offer.

Kunstigaleriist pART on võimalik tellida näitust tutvustavaid loenguid / Ülle Lätte

Index Scriptorium Estoniae

Lätte, Ülle, 1955-

2008-01-01

Kunstigalerii pART näitusel "Nad rõõmustavad meid" eksponeeritakse Põltsamaalt pärit kunstnike Tiit Pääsukese, Peeter Alliku, Toivo Raidmetsa, Viive Väljaotsa, Mare Tralla, Ave Nahkuri, Peep Pedmansoni loomingut

Carvacrol attenuates N-nitrosodiethylamine induced liver injury in experimental Wistar rats

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Balan Rajan

2015-06-01

Full Text Available Carvacrol is a main constituent in the essential oils of countless aromatic plants including Origanum Vulgare and Thymus vulgari, which has been assessed for substantial pharmacological properties. In recent years, notable research has been embarked on to establish the biological actions of Carvacrol for its promising use in clinical applications. The present study is an attempt to reveal the protective role of Carvacrol against N-Nitrosodiethylamine (DEN induced hepatic injury in male Wistar albino rats. DEN is an egregious toxin, present in numerous environmental factors, which enhances chemical driven liver damage by inducing oxidative stress and cellular injury. Administration of DEN (200 mg/kg bodyweight, I.P to rats results in elevated marker enzymes (in both serum and tissue. Carvacrol (15 mg/kg body weight suppressed the elevation of marker enzymes (in both serum and tissue and augmented the antioxidants levels. The hoisted activities of Phase I enzymes and inferior activities of Phase II enzymes were observed in DEN-administered animals, whereas Carvacrol treated animals showed improved near normal activity. Histological observations also support the protective role of Carvacrol against DEN induced liver damage. Final outcome from our findings intimate that Carvacrol might be beneficial in attenuating toxin induced liver damage.

The metalloid arsenite induces nuclear export of Id3 possibly via binding to the N-terminal cysteine residues

International Nuclear Information System (INIS)

Kurooka, Hisanori; Sugai, Manabu; Mori, Kentaro; Yokota, Yoshifumi

2013-01-01

Highlights: •Sodium arsenite induces cytoplasmic accumulation of Id3. •Arsenite binds to closely spaced N-terminal cysteine residues of Id3. •N-terminal cysteines are essential for arsenite-induced nuclear export of Id3. •Nuclear export of Id3 counteracts its transcriptional repression activity. -- Abstract: Ids are versatile transcriptional repressors that regulate cell proliferation and differentiation, and appropriate subcellular localization of the Id proteins is important for their functions. We previously identified distinct functional nuclear export signals (NESs) in Id1 and Id2, but no active NES has been reported in Id3. In this study, we found that treatment with the stress-inducing metalloid arsenite led to the accumulation of GFP-tagged Id3 in the cytoplasm. Cytoplasmic accumulation was impaired by a mutation in the Id3 NES-like sequence resembling the Id1 NES, located at the end of the HLH domain. It was also blocked by co-treatment with the CRM1-specific nuclear export inhibitor leptomycin B (LMB), but not with the inhibitors for mitogen-activated protein kinases (MAPKs). Importantly, we showed that the closely spaced N-terminal cysteine residues of Id3 interacted with the arsenic derivative phenylarsine oxide (PAO) and were essential for the arsenite-induced cytoplasmic accumulation, suggesting that arsenite induces the CRM1-dependent nuclear export of Id3 via binding to the N-terminal cysteines. Finally, we demonstrated that Id3 significantly repressed arsenite-stimulated transcription of the immediate-early gene Egr-1 and that this repression activity was inversely correlated with the arsenite-induced nuclear export. Our results imply that Id3 may be involved in the biological action of arsenite

Radiation-induced bystander effects: Are they good bad or both?

International Nuclear Information System (INIS)

Le Guen, B.; Lallemand, J.; Averbeck, D.; Chetioui, A.; Gardes-Albert, M.; Mothersill, C.; Gourmelon, P.; Benderitter, M.; Chevillard, S.; Martin, M.; Verrelle, P.

2004-01-01

The different contributions are as follow: the current events on the cellular responses to irradiation ( part one and two); From physico-chemistry to radiobiology: new knowledge (part one and two); Radiation-induced bystander effects: are they good bad or both; recognition of the multi visceral failure in the acute irradiation syndrome; integrated approach of the tissue carcinogenesis: differential effect sane tissue-tumoral tissue; differential diagnosis of thyroid cancers by the transcriptoma analysis. (N.C.)

Effect of the methanolic extracts of different parts of Ferula assa-foetida on naloxone-induced withdrawal behavior in morphine-dependent mice

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Mahnaz Khanavi

2017-08-01

Full Text Available Objective: Ferula assa-foetida, a native species in Iran, is used for treatment of several diseases particularly for neurological disorders in Iranian Traditional Medicine. The aim of this study is to investigate the effect of methanolic roots, fruits, and aerial parts extracts of Ferula assa-foetida on withdrawal syndrome in morphine-dependent mice. Materials and Methods: Aerial parts, roots, and fruits of the plant were separately extracted with 80% MeOH. For induction of dependence, morphine (50, 50 and 75 mg/kg was injected subcutaneously three times daily (10 am, 1 pm and 4 pm for three days and a last dose of morphine (50 mg/kg was administrated on the fourth day. Withdrawal syndrome was induced by injection of naloxone (5 mg/kg, intraperitoneal 2 hr after the final dose of morphine. Different doses of the extracts were administered i.p. 60 minutes before naloxone injection and withdrawal sign was recorded 2 minutes after naloxone injection for a period of 60 minutes.   Results: Pre-treatment of animals with different doses (2.5, 5, 10, 20 mg/kg of methanolic extract of the aerial parts of F. assa-foetida caused a significant decrease in naloxone-induced behavior. Intraperitoneal administration of different doses (10, 15, 20, 25 mg/kg of methanolic extract of the fruit significantly reduced the naloxone-induced withdrawal behavior (p

High-performance germanium n+/p junction by nickel-induced dopant activation of implanted phosphorus at low temperature

International Nuclear Information System (INIS)

Huang Wei; Lu Chao; Yu Jue; Wei Jiang-Bin; Chen Chao-Wen; Wang Jian-Yuan; Xu Jian-Fang; Li Cheng; Chen Song-Yan; Lai Hong-Kai; Wang Chen; Liu Chun-Li

2016-01-01

High-performance Ge n + /p junctions were fabricated at a low formation temperature from 325 °C to 400 °C with a metal(nickel)-induced dopant activation technique. The obtained NiGe electroded Ge n + /p junction has a rectification ratio of 5.6× 10 4 and a forward current of 387 A/cm 2 at −1 V bias. The Ni-based metal-induced dopant activation technique is expected to meet the requirement of the shallow junction of Ge MOSFET. (paper)

Heavy ion irradiation induced effects in Ni3N/Al bilayers

International Nuclear Information System (INIS)

Dhar, S.; Rissanen, L.; Engel, K.; Wenderoth, M.; Lieb, K.P.

2001-01-01

The article reports on the Xe ion beam irradiation studies of Ni 3 N/Al bilayers at 80 K. The ion-induced modifications were monitored by Rutherford backscattering (RBS), resonant nuclear reaction analysis (RNRA), X-ray diffraction (XRD) and atomic force microscopy (AFM). We found preferential loss of nitrogen from the surface region of the Ni 3 N top layers. The surface roughness Δσ S and the interface broadening variance Δσ int 2 increase linearly with the Xe ion fluence PHI. The experimental mixing rate of Δσ 2 /PHI=1.8 nm 4 is explained by considering an enhancement of ballistic mixing due to chemical reactions at the interface

Menthol Enhances Nicotine Reward-Related Behavior by Potentiating Nicotine-Induced Changes in nAChR Function, nAChR Upregulation, and DA Neuron Excitability.

Science.gov (United States)

Henderson, Brandon J; Wall, Teagan R; Henley, Beverley M; Kim, Charlene H; McKinney, Sheri; Lester, Henry A

2017-11-01

Understanding why the quit rate among smokers of menthol cigarettes is lower than non-menthol smokers requires identifying the neurons that are altered by nicotine, menthol, and acetylcholine. Dopaminergic (DA) neurons in the ventral tegmental area (VTA) mediate the positive reinforcing effects of nicotine. Using mouse models, we show that menthol enhances nicotine-induced changes in nicotinic acetylcholine receptors (nAChRs) expressed on midbrain DA neurons. Menthol plus nicotine upregulates nAChR number and function on midbrain DA neurons more than nicotine alone. Menthol also enhances nicotine-induced changes in DA neuron excitability. In a conditioned place preference (CPP) assay, we observed that menthol plus nicotine produces greater reward-related behavior than nicotine alone. Our results connect changes in midbrain DA neurons to menthol-induced enhancements of nicotine reward-related behavior and may help explain how smokers of menthol cigarettes exhibit reduced cessation rates.

Recycling industrial waste in brick manufacture. Part 1

Directory of Open Access Journals (Sweden)

Andreola, F.

2005-12-01

Full Text Available The ongoing accumulation of industrial waste speaks to the need to seek cost-effective disposal methods. Brick manufacture would appear to be particularly promising in this regard. The present study analyzes the possibility of recycling the sludge generated in porcelain tile polishing, as well as coal, steel and municipal incinerator ash to make a special type of facing brick whose properties readily accommodate a full analysis of all the problems deriving from the incorporation of residue in its manufacture. Physical-chemical, mechanical and structural analyses were performed on bricks made with varying percentages of the different types of waste considered. This first paper reports the results of the physical arid technological characterization of the products; the second part of the research will address their chemical, mechanical and structural properties.

El continuo aumento de la cantidad de residuos (desechos que se generan en los procesos industriales induce a buscar nuevos métodos alternativos a la disposición final que sean altamente eficientes y a bajo costo. La industria manufac turera de ladrillos resulta muy prometedora desde este punto de vista. En este trabajo ha sido investigada la posibilidad de usar distintos residuos industriales, entre ellos barros de pulido del gres porcelánico. cenizas de carbón, cenizas de acerías y de incinerador municipal para la fabricación de ladrillos de exteriores. Fueron analizados los problemas que podrían derivar al introducir estos residuos en la pasta. En particular, en esta primera parte del trabajo se muestran los resultados derivados de la introducción de los residuos considerados, en distintos porcentajes, sobre las propiedades físicas y tecnológicas del producto final. En la segunda parte se desarrollarán los efectos causados sobre las propiedades químicas, mecánicas y microestructurales.

Mechanism of the protective effects of long chain n-alkyl glucopyranosides against ultrasound-induced cytolysis of HL-60 cells

OpenAIRE

Cheng, Jason Y.; Riesz, Peter

2007-01-01

Recently it has been shown that long chain (C5 to C8) n-alkyl glucopyranosides completely inhibit ultrasound-induced cytolysis [1]. This protective effect has possible applications in HIFU (high intensity focused ultrasound) for tumor treatment, and in ultrasound assisted drug delivery and gene therapy. n-Alkyl glucopyranosides with hexyl (5mM), heptyl (3mM), octyl (2mM) n-alkyl chains protected 100% of HL-60 cells in-vitro from 1.057 MHz ultrasound induced cytolysis under a range of conditio...

Simulación de la fluencia en caliente de un acero microaleado con un contenido medio de carbono. III parte. Ecuaciones constitutivas

Directory of Open Access Journals (Sweden)

Cabrera, J. M.

1997-08-01

Full Text Available According to the part 1 of this work the constitutive equations of the hot flow behaviour of a commercial microalloyed steel have been obtained. For this purpose, the uniaxial hot compression tests described in the part 2 were employed. Tests were carried out over a range of 5 orders of magnitude in strain rate and 300 °C of temperature. Experimental results are compared with the theoretical model introduced in the first part of this study. It is concluded that deviations between experimental and theoretical curves are lower than 10 %. It is shown that the classical hiperbolic sine constitutive equation described accurately the experimental behaviour provided that stresses are normalized by the Young's modulus and strain rates by the self-diffusion coefficient. An internal stress must also be introduced in the latter equation when the initial grain size is fine enough.

Siguiendo el planteamiento teórico efectuado en la I parte de este trabajo, se determinaron las ecuaciones constitutivas del comportamiento a la deformación en caliente de un acero comercial microaleado con un contenido medio de carbono. Para este objetivo se emplearon los ensayos de compresión uniaxial en caliente ya descritos en la II parte, los cuales se efectuaron en un rango de cinco órdenes de magnitud en velocidad de deformación y 300 °C de temperatura. Se comparan los resultados experimentales con el modelo teórico introducido en la I parte y se verifica que el error es inferior al 10 %. Se comprobó que la clásica ecuación del seno hiperbólico podía describir con precisión el comportamiento observado siempre y cuando las tensiones se normalicen por el módulo de Young, las velocidades de deformación por el coeficiente de autodifusión de la austenita, y se considere un efecto adicional sobre la tensión cuando el tamaño de grano inicial sea suficientemente fino.

Effect of N-Acetylcysteine in Protecting from Simultaneous Noise and Carbon Monoxide Induced Hair Cell Loss

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Akram Pourbakht

2011-06-01

Full Text Available Background and Aim: N-acetylcysteine, a glutathione precursor and reactive oxygen species scavenger, is reported to be effective in reducing noise-induced hearing loss. Many workers in industry are exposed simultaneously to noise and chemical pollutants such as carbon monoxide. We investigated effectiveness of N-acetylcysteine in protecting the cochlea from simultaneous noise and carbon monoxide damages.Methods: Twelve rabbits were exposed simeltaneously to 100 dB sound pressure level of broad band noise and carbon monoxide 8 hours a day for 5 days. One hour before exposure, experimental group received 325 mg/kg of N-acetylcysteine while normal saline was administered for the control group. The protective effect of N-acetylcysteine was evaluated 3 weeks after exposure by histological assessment of the hair cells.Results: Simultaneous exposure to noise and carbon monoxide resulted in a considerable damage to the outer hair cells; however, the inner hair cells and the pillar cells remained intact. Use of N-acetylcysteine in the experimental group significantly reduced the extent of outer hair cell loss.Conclusion: N-acetylcysteine attenuates simultaneous noise and carbon monoxide induced hair cell damage in rabbits.

TRASMISIÓN DE BIENES Y REGISTRO DE LA PROPIEDAD EN ESPAÑA (SEGUNDA PARTE

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Joaquín Sánchez Cebrián

2009-01-01

Full Text Available La circulación de los bienes en el tráfico jurídico por la voluntad de los particulares es un tema crucial que interesa, no sólo a las partes del contrato, sino, a todos en general, y, en particular, a los acreedores del transmitente o del adquirente y a los terceros adquirentes de derechos sobre el bien. En este trabajo se analizará el régimen de trasmisión de los bienes por negocio inter vivos en el Derecho español, dentro del marco europeo, y con particular referencia a la trasmisión inmobiliaria. España adopta un peculiar sistema de trasmisión de los bienes porque se establecen reglas genéricas cuya aplicación se da con independencia de la naturaleza mueble o inmueble del bien; pero a su lado se superponen otras que tratan de fijar los efectos de la publicidad registral inmobiliaria. La coordinación entre dichas reglas produce un original resultado, que puede constituir el punto de encuentro de los diversos sistemas registrales europeos.

78 FR 47817 - Parts and Accessories Necessary for Safe Operation; Application for an Exemption From Van Hool N...

Science.gov (United States)

2013-08-06

... DEPARTMENT OF TRANSPORTATION Federal Motor Carrier Safety Administration [Docket No. FMCSA-2013-0314] Parts and Accessories Necessary for Safe Operation; Application for an Exemption From Van Hool N... exemption from Van Hool N.V. and Coach USA (Van Hool/Coach USA) to allow the use of double deck motorcoaches...

Síndrome de dolor miofacial de cabeza y cuello: II parte: caracterización gráfica

Directory of Open Access Journals (Sweden)

José Manuel Díaz Fernández¹

1996-08-01

Full Text Available Se realizó un estudio de complementación de los aspectos clínicos del síndrome de dolor miofacial de la cabeza y el cuello (parte I, cuyo fundamento científico se basa en el diseño gráfico de figuras humanas en su porción craneocervicofacial, donde se esquematizan los puntos de transmisión de dolor "activo" o "latente" en el complejo muscular de ambas regiones, así como las áreas de referencia de dolores primario y secundario de la zona craneal y maxilofacial. Se describe la técnica de palpación apropiada para la identificación de estos puntos.A complementary study of the clinical aspects of head and neck myofacial pain syndrome (Part 1, was carried out; its scientific foundation is based on the graphical design of human figures in their cranio-cervico-facial portion, where the "active" or "latent" pain triggering points in the muscular complex of both regions were taken into schemes, as well as the reference areas of primary and secondary pain of the cranial and maxillofacial zones. The adequate palpation technique for the identification of these points, is described.

Numerical and Experimental Study on Negative Buoyance Induced Vortices in N-Butane Jet Flames

KAUST Repository

Xiong, Yuan; Cha, Min; Chung, Suk-Ho

2015-01-01

Near nozzle flow field in flickering n-butane diffusion jet flames was investigated with a special focus on transient flow patterns of negative buoyance induced vortices. The flow structures were obtained through Mie scattering imaging with seed

Cross sections for the (n,p), (n,α) and (n,2n) threshold reactions

International Nuclear Information System (INIS)

Bychkov, V.M.; Manokhin, V.N.; Pashchenko, A.B.; Plyaskin, V.I.

1980-07-01

The (n,p), (n,α), (n,2n) threshold reactions are reviewed for nuclei with Z>=20 in the neutron energy range from the threshold up to 20MeV. The review consists of four parts. In the first part the theoretical methods of cross-section calculations and the empirical or semi-empirical systematics are considered. In the second, third and fourth parts the experimental data compilations on the (n,p), (n,α) and (n,2n) excitation functions are given. The recommended values of cross-sections at 14.5MeV neutron energy are given in tables. For some isotopes the recommended curves of excitation functions also are given in graphs. (author)

10 CFR Appendix N to Part 50 - Standardization of Nuclear Power Plant Designs: Permits To Construct and Licenses To Operate...

Science.gov (United States)

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Standardization of Nuclear Power Plant Designs: Permits To Construct and Licenses To Operate Nuclear Power Reactors of Identical Design at Multiple Sites N Appendix N... FACILITIES Pt. 50, App.N Appendix N to Part 50—Standardization of Nuclear Power Plant Designs: Permits To...

Swift heavy-ion induced trap generation and mixing at Si/SiO{sub 2} interface in depletion n-MOS

Energy Technology Data Exchange (ETDEWEB)

Shinde, N. [Ecotopia Science Institute, Division of Energy Science, Nagoya University, Nagoya 464-8603 (Japan) and Department of Physics, University of Pune, Pune 411 007 (India)]. E-mail: nss@nucl.nagoya-u.ac.jp; Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411 007 (India)

2006-01-15

Large channel depletion n-channel MOSFET (Metal oxide semiconductor field effect transistor) is a basic Si-SiO{sub 2} structure to understand irradiation-induced modifications. The contribution of interface and oxide states denoted as {delta}N {sub IT} and {delta}N {sub OT}, respectively, was separated out by using I {sub D}-V {sub DS}, I {sub D}-V {sub GS} measurements. The threshold voltage shift {delta}V {sub T} (V {sub T-irrad} - V {sub T-virgin}) increased for all ions (50 MeV Li, B, F, P and Ni) over the fluence of 2 x 10{sup 11}-2 x 10{sup 13} ions/cm{sup 2}. The increase in {delta}N {sub IT} was associated to trap generation at Si-SiO{sub 2} interface, but a small change in {delta}N {sub OT} indicate less charge trapping in oxide. The electronic energy loss S {sub e} induced increase in {delta}N {sub IT} is not adequate to explain the large shift in threshold voltage. A rough estimate shows that the channel width, W should decrease by 40% for a large increase in {delta}N {sub IT}. Thus, the possible factor affecting reduction of W may be ion beam mixing induced broadening of Si-SiO{sub 2} interface.

Differential response of nNOS knockout mice to MDMA ("ecstasy")- and methamphetamine-induced psychomotor sensitization and neurotoxicity.

Science.gov (United States)

Itzhak, Yossef; Anderson, Karen L; Ali, Syed F

2004-10-01

It has been shown that mice deficient in neuronal nitric oxide synthase (nNOS) gene are resistant to cocaine-induced psychomotor sensitization and methamphetamine (METH)-induced dopaminergic neurotoxicity. The present study was undertaken to investigate the hypothesis that nNOS has a major role in dopamine (DA)- but not serotonin (5-hydroxytryptamine; 5-HT)-mediated effects of psychostimulants. The response of nNOS knockout (KO) and wild-type (WT) mice to the psychomotor-stimulating and neurotoxic effects of 3,4-methylenedioxymethamphetamine (MDMA; "Ecstasy") and METH were investigated. Repeated administration of MDMA for 5 days resulted in psychomotor sensitization in both WT and nNOS KO mice, while repeated administration of METH caused psychomotor sensitization in WT but not in KO mice. Sensitization to both MDMA and METH was persistent for 40 days in WT mice, but not in nNOS KO mice. These findings suggest that the induction of psychomotor sensitization to MDMA and METH is NO independent and NO dependent, respectively, while the persistence of sensitization to both drugs is NO dependent. For the neurochemical studies, a high dose of MDMA caused marked depletion of 5-HT in several brain regions of both WT and KO mice, suggesting that the absence of the nNOS gene did not afford protection against MDMA-induced depletion of 5-HT. Striatal dopaminergic neurotoxicity caused by high doses of MDMA and METH in WT mice was partially prevented in KO mice administered with MDMA, but it was fully precluded in KO mice administered with METH. The differential response of nNOS KO mice to the behavioral and neurotoxic effects of MDMA and METH suggests that the nNOS gene is required for the expression and persistence of DA-mediated effects of METH and MDMA, while 5-HT-mediated effects of MDMA (induction of sensitization and 5-HT depletion) are not dependent on nNOS.

L-3-n-Butylphthalide Protects HSPB8 K141N Mutation-Induced Oxidative Stress by Modulating the Mitochondrial Apoptotic and Nrf2 Pathways

Directory of Open Access Journals (Sweden)

Xiao-Dong Yang

2017-07-01

Full Text Available Charcot–Marie–Tooth disease (CMT, also known as hereditary motor and sensory neuropathy, is the most common inherited peripheral nerve disorder. Missense mutations, such as K141N, in the small heat shock protein HSPB8 are known to cause distal hereditary motor neuropathy 2A (dHMN2A or Charcot-Marie-Tooth neuropathy type 2L (CMT2L. However, of critical clinical significance, very few specific therapies for this disease exist. In the present study, we investigated the impact of mutant K141N HSPB8 on mitochondrial distribution and function in a cellular model of CMT2L. Our results indicate that K141N HSPB8 induced mitochondrial aggregation and caused increased oxidative stress injury. As an extraction from Chinese celery Apium graveolens Linn seeds, L-3-n-Butylphthalide (NBP, has been reported to exert many neuroprotective effects, we interrogated whether NBP could elicit a protective effect on the cell injury typically caused by HSPB8 K141N mutations. We found NBP could reverse the pathological processes induced by HSPB8 K141N mutation via an antioxidant effect, modulation of the Bax/Bcl-2 mitochondrial apoptotic and Nrf2 pathways. We propose a novel function of HSPB8, highlighting the consequence of the K141N pathogenic mutation. Furthermore, we suggest NBP may have promising therapeutic potential in the treatment of CMT2L.

N{sup +} ion-implantation-induced defects in ZnO studied with a slow positron beam

Energy Technology Data Exchange (ETDEWEB)

Chen, Z Q [Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan (Japan); Sekiguchi, T [Nanomaterials Laboratory, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Yuan, X L [Nanomaterials Laboratory, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Maekawa, M [Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan (Japan); Kawasuso, A [Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan (Japan)

2004-01-21

Undoped ZnO single crystals were implanted with multiple-energy N{sup +} ions ranging from 50 to 380 keV with doses from 10{sup 12} to 10{sup 14} cm{sup -2}. Positron annihilation measurements show that vacancy defects are introduced in the implanted layers. The concentration of the vacancy defects increases with increasing ion dose. The annealing behaviour of the defects can be divided into four stages, which correspond to the formation and recovery of large vacancy clusters and the formation and disappearance of vacancy-impurity complexes, respectively. All the implantation-induced defects are removed by annealing at 1200 deg. C. Cathodoluminescence measurements show that the ion-implantation-induced defects act as nonradiative recombination centres to suppress the ultraviolet (UV) emission. After annealing, these defects disappear gradually and the UV emission reappears, which coincides with positron annihilation measurements. Hall measurements reveal that after N{sup +} implantation, the ZnO layer still shows n-type conductivity.

Effects of flooding-induced N2O production, consumption and emission dynamics on the annual N2O emission budget in wetland soil

DEFF Research Database (Denmark)

Jørgensen, Christian Juncher; Elberling, Bo

2012-01-01

during mid-summer when the WL was at its seasonally lowest counterbalancing ~6.4% of the total annual net N2O emission budget. Main surface emission periods of N2O were observed when the water level and associated peaks in subsurface N2O concentrations were gradually decreasing to soil depths down to 40...... production and consumption capacities where >500 nmol N2O cm-3 were sequentially produced and consumed in less than 24 hrs. It is concluded that a higher future frequency of flooding induced N2O emissions will have a very limited effect on the net annual N2O emission budget as long as NO3- availability...

Simulación de la fluencia en caliente de un acero microaleado con un contenido medio de carbono. II parte. Recristalización dinámica: inicio y cinética

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Cabrera, J. M.

1997-06-01

Full Text Available According to the part 1 of this work, in this second part the dynamic recrystallization of a commercial medium carbon microalloyed steel is characterized from the point of view of its onset and kinetics. For this purpose uniaxial hot compression tests were carried out over a range of five orders of magnitude in strain rate and 300 °C of temperature. Experimental results are compared with those reported in the literature and the possible effect of dynamic precipitation is also analyzed. It is verified that the kinetics of dynamic recrystallization can faithfully be described by the classical Avrami equation.

Siguiendo el planteamiento efectuado en la I parte de este trabajo, en esta II parte se caracteriza la recristalización dinámica de un acero comercial microaleado con un contenido medio de carbono desde el punto de vista de su inicio y de su cinética. Con este objeto se efectuaron ensayos de compresión uniaxial en caliente en un intervalo de cinco órdenes de magnitud en velocidad de deformación y 300 °C de temperatura. Los resultados experimentales se comparan con los resultados reportados por diversos autores y se analizan los posibles efectos de precipitación dinámica. Se verifica que la cinética de la recristalización dinámica puede representarse fielmente por la ecuación de Avrami.

Gomisin N ameliorates lipopolysaccharide-induced depressive-like behaviors by attenuating inflammation in the hypothalamic paraventricular nucleus and central nucleus of the amygdala in mice

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Ryota Araki

2016-10-01

Full Text Available Emotional impairments such as depressive symptoms often develop in patients with sustained and systemic immune activation. The objective of this study is to investigate the effect of gomisin N, a dibenzocyclooctadiene lignan isolated from the dried fruits of Schisandra chinensis (Turcz. Baill., which exhibited inhibitory effects of the bacterial endotoxin lipopolysaccharide (LPS-induced NO production in a screening assay, on inflammation-induced depressive symptoms. We examined the effects of gomisin N on inflammation induced by LPS in murine microglial BV-2 cells and on LPS-induced behavioral changes in mice. Gomisin N inhibited LPS-induced expression of mRNAs for inflammation-related genes (inducible nitric oxide synthase (iNOS, cyclooxygenase (COX-2, interleukin (IL-1β, IL-6 and tumor necrosis factor (TNF-α in BV-2 cells. Administration of gomisin N attenuated LPS-induced expression of mRNAs for inflammation-related genes, increases in the number of c-Fos immunopositive cells in the hypothalamus and amygdala, depressive-like behavior in the forced swim test and exploratory behavior deficits 24 h after LPS administration in mice. These results suggest that gomisin N might ameliorate LPS-induced depressive-like behaviors through inhibition of inflammatory responses and neural activation in the hypothalamus and amygdala.

Evolución del Arsenal Científico para la Vigilancia de la Capa de Ozono Parte II

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J C. González N.

2009-07-01

Full Text Available Los propósitos de este trabajo son: a describir los dominios en los que se centra parte de la literatura científica reciente, relacionada con la evaluación de la columna total de ozono y con los niveles de radiación solar ultravioleta B (RUVB; b resaltar las más importantes estrategias desarrolladas en el abordaje del análisis y seguimiento de la capa de ozono; c hallar las tendencias de asociación científica para la investigación de la capa de ozono; d sugerir el ámbito en el cual los países Andinos pueden formar parte de la comunidad científica que estudia los niveles de la radiación ultravioleta solar en la superficie terrestre. Metodológicamente, se toman los hilos históricos de los criterios científicos que determinaron los avances teóricos e instrumentales que han conducido al nivel de desarrollo científico y tecnológico disponibles en la actualidad. Se encuentra que, después de más de treinta y cinco años de enunciado el problema ambiental de carácter global, se ha formado y organizado una amplia y fuerte comunidad científica internacional que desplegando esfuerzos, ha logrado direccionar y motivar a muchos sectores, desde los más altos niveles de gobierno de las organizaciones internacionales, para controlar sustancias antropogénicas que emitidas a la atmósfera, le hacen daño a la capa de ozono. Se ha logrado reducir las emisiones de las sustancias de primera generación en más de 95 %, pero dado que la mayor parte de ellas permanecerán en la atmosfera por al menos 40 o 50 años, se requiere continuar con los esfuerzos para mejorar los métodos de control y medición existentes y encontrar otros, más precisos, funcionales y económicos.

A CVD Diamond Detector for (n,a) Cross-Section Measurements

CERN Document Server

Weiss, Christina; Griesmayer, Erich; Guerrero, Carlos

A novel detector based on the chemical vapor deposition (CVD) diamond technology has been developed in the framework of this PhD, for the experimental determination of (n,a) cross-sections at the neutron time-of-flight facility n_TOF at CERN. The 59Ni(n,a)56Fe cross-section, which is relevant for astrophysical questions as well as for risk-assessment studies in nuclear technology, has been measured in order to validate the applicability of the detector for such experiments. The thesis is divided in four parts. In the introductory part the motivation for measuring (n,a) cross-sections, the experimental challenges for such measurements and the reasons for choosing the CVD diamond technology for the detector are given. This is followed by the presentation of the n_TOF facility, an introduction to neutron-induced nuclear reactions and a brief summary of the interaction of particles with matter. The CVD diamond technology and the relevant matters related to electronics are given as well in this first part of the t...

The effects of antiepileptic inducers in neuropsychopharmacology, a neglected issue. Part I: A summary of the current state for clinicians.

Science.gov (United States)

de Leon, Jose

2015-01-01

The literature on inducers in epilepsy and bipolar disorder is seriously contaminated by false negative findings. This is part i of a comprehensive review on antiepileptic drug (AED) inducers using both mechanistic pharmacological and evidence-based medicine to provide practical recommendations to neurologists and psychiatrists concerning how to control for them. Carbamazepine, phenobarbital and phenytoin, are clinically relevant AED inducers; correction factors were calculated for studied induced drugs. These correction factors are rough simplifications for orienting clinicians, since there is great variability in the population regarding inductive effects. As new information is published, the correction factors may need to be modified. Some of the correction factors are so high that the drugs (e.g., bupropion, quetiapine or lurasidone) should not co-prescribed with potent inducers. Clobazam, eslicarbazepine, felbamate, lamotrigine, oxcarbazepine, rufinamide, topiramate, vigabatrin and valproic acid are grouped as mild inducers which may (i)be inducers only in high doses; (ii)frequently combine with inhibitory properties; and (iii)take months to reach maximum effects or de-induction, definitively longer than the potent inducers. Potent inducers, definitively, and mild inducers, possibly, have relevant effects in the endogenous metabolism of (i)sexual hormones, (ii) vitamin D, (iii)thyroid hormones, (iv)lipid metabolism, and (v)folic acid. Copyright © 2014 SEP y SEPB. Published by Elsevier España. All rights reserved.

Involvement of PKA-dependent upregulation of nNOS-CGRP in adrenomedullin-initiated mechanistic pathway underlying CFA-induced response in rats.

Science.gov (United States)

Wang, Dongmei; Ruan, Liqin; Hong, Yanguo; Chabot, Jean-Guy; Quirion, Rémi

2013-01-01

We have previously shown that intrathecal administration of the adrenomedullin (AM) receptor antagonist AM(22-52) produces a long-lasting anti-hyperalgesia effect. This study examined the hypothesis that AM recruits other pronociceptive mediators in complete Freund's adjuvant (CFA)-induced inflammation. Injection of CFA in the hindpaw of rat produced an increase in the expression of nNOS in dorsal root ganglion (DRG) and the spinal dorsal horn. An intrathecal administration of AM(22-52), but not the CGRP antagonist BIBN4096BS, abolished the CFA-induced increase of nNOS. Moreover, AM-induced increase of CGRP was inhibited by the nNOS inhibitors L-NAME and 7-nitroindazole in cultured ganglion explants. Addition of AM to ganglion cultures induced an increase in nNOS protein, which was attenuated by the PKA inhibitor H-89. Treatment with AM also concentration-dependently increased cAMP content and pPKA protein level, but not its non-phosphorylated form, in cultured ganglia. In addition, nNOS was shown to be co-localized with the AM receptor components calcitonin receptor-like receptor and receptor activity-modifying protein 2- and 3 in DRG neurons. The present study suggests that the enhanced activity of nitric oxide (NO) mediates the biological action of AM at the spinal level and that AM recruits NO-CGRP via cAMP/PKA signaling in a mechanistic pathway underlying CFA-induced hyperalgesia. Copyright © 2012 Elsevier Inc. All rights reserved.

Autoestima y adaptación en víctimas de maltrato psicológico por parte de la parej

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Luz E. Ocampo Otálvaro

2015-01-01

Full Text Available El objetivo de este trabajo fue evaluar los niveles de autoestima y adaptación en un grupo de personas con experiencia de maltrato por parte de su pareja en la ciudad de Medellín (Colombia. Se utilizó un diseño transversal, ex post facto; se llevó a cabo un muestreo no probabilístico y se seleccionaron 50 sujetos. Los instrumentos utilizados fueron una entrevista semiestructurada, un cuestionario de autoestima y uno de adaptación. Se realizaron análisis descriptivos y de porcentajes. Los resultados mostraron bajos niveles de autoestima y elevados índices de inadaptación; igualmente, se encontró que el tipo de maltrato más común es el psicológico, el cual se acompaña de agresión física, sexual y económica; además, las mujeres fueron quienes más reportaron ser víctimas de esta situación. En conclusión, las personas que son víctimas de maltrato por parte de su pareja tienden a mostrar más bajos niveles de autoestima y más altos índices de inadaptación.

Interacción térmica recubrimiento-sustrato en la proyección a alta velocidad (HVOF de partículas (polvo de WC-Co

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Sobolev, V. V.

1995-06-01

Full Text Available The mathematical simulation of the thermal interaction between a 34CrMo4 (UNS-G41350 steel substrate and a coating formed by the droplets of WC-12 % Co powder particles during HVOF spraying is undertaken. Analysis of the heat transfer processes permitted the investigation of the temperature evolution, coating solidification, substrate fusion and solidification, particular features of the thermal interactions between the substrate and the coating as well as between the successive coating layers. The analysis has also permitted to estimate the optimal conditions of the substrate and the coating structure formation. The obtained results were used in subsequent articles to predict the structure parameters, which agree with the experimental data.

Se utiliza la simulación matemática para establecer la interacción térmica entre un substrato y un recubrimiento obtenido mediante proyección térmica de alta velocidad, HVOF. El substrato es un acero 34CrMo4(UNS-G41350 y el recubrimiento está formado por la solidificación de gotas semifundidas de partículas de polvo de WC-12 % Co. El análisis del proceso de transferencia de calor permite la investigación de la evolución de la temperatura, la solidificación del recubrimiento, la fusión y posterior solidificación del substrato, las características peculiares de la interacción térmica entre el substrato y la primera capa de recubrimiento, así como con las diferentes capas sucesivas, y la estimación de las condiciones óptimas para la formación de la estructura del substrato y del recubrimiento. Los resultados obtenidos se han utilizado en posteriores artículos para predecir parámetros estructurales que están, por su parte, en concordancia con los datos experimentales.

Blockade of N-methyl-D-aspartate induced convulsions by 1-aminocyclopropanecarboxylates

International Nuclear Information System (INIS)

Skolnick, P.; Marvizon, J.C.G.; Jackson, B.W.; Monn, J.A.; Rice, K.C.; Lewin, A.H.

1989-01-01

1-Aminocyclopropanecarboxylic acid is a potent and selective ligand for the glycine modulatory site on the N-methyl-D-aspartate receptor complex. This compound blocks the convulsions and deaths produced by N-methyl-D-aspartate in a dose dependent fashion. In contrast, 1-aminocyclopropanecarboxylic acid does not protect mice against convulsions induced by pentylenetetrazole, strychnine, bicuculline, or maximal electroshock, and does not impair motor performance on either a rotarod or horizontal wire at doses of up to 2 g/kg. The methyl- and ethyl- esters of 1-aminocyclopropanecarboxylic acid are 5- and 2.3-fold more potent, respectively, than the parent compound in blocking the convulsant and lethal effects of N-methyl-D-aspartate. However, these esters are several orders of magnitude less potent than 1-aminocyclopropanecarboxylic acid as inhibitors of strychnine-insensitive [ 3 H]glycine binding, indicating that conversion to the parent compound may be required to elicit an anticonvulsant action

The Green Tea Component (--Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity.

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Jee-Youn Kim

Full Text Available The green tea component (--epigallocatechin-3-gallate (EGCG has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose polymerase (PARP, activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As treatment significantly induced production of reactive oxygen species (ROS, which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK, which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity.

The Green Tea Component (-)-Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity.

Science.gov (United States)

Kim, Jee-Youn; Choi, Ji-Young; Lee, Hyeon-Ju; Byun, Catherine Jeonghae; Park, Jung-Hyun; Park, Jae Hoon; Cho, Ho-Seong; Cho, Sung-Jin; Jo, Sangmee Ahn; Jo, Inho

2015-01-01

The green tea component (-)-epigallocatechin-3-gallate (EGCG) has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As) or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC) at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose) polymerase (PARP), activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As) treatment significantly induced production of reactive oxygen species (ROS), which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK), which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity.

Comparative Anti-Diabetic Evaluation of Different Parts of Himalrandia tetrasperma in Alloxan Induced Diabetic in Mice

International Nuclear Information System (INIS)

Ajaib, M.

2016-01-01

The present experiments were designed to investigate the acute effects of methanolic extracts of various parts of H. tetrasperma in diabetic mice. The basic phyto-chemical study showed the occurrence of alkaloids, saponins, flavonoids and tannins as main phyto-constituents in the methanolic extract. Diabetes was induced experimentally in mice by intra peritoneally injecting alloxan (150 mg/kg i.p.). In acute study, methanolic H. tetrasperma extracts of various parts of plant were evaluated for anti-diabetic potential in alloxan induced diabetic mice. Extracts of leaves, bark and seeds (250 mg/kg, i.p) and metformin (250 mg/kg i.p) were given intra peritoneal in alloxan treated diabetic mice and blood glucose levels were measured at 0, 360 and 24 h. There was significant lowering of blood glucose level at 1 h after treatment, in diabetic mice treated with methanolic extracts of bark (182.3 ± 3.6 mg/dL), leaves (178.5 ± 1.2 mg/dL) and seeds (156.3 ± 11.3 mg/dL) when compared with control diabetic group (280 ± 7.92 mg/dL). Highly significant results were also obtained at 24 h after treatment with methanolic extracts of bark (187.67 ±1.2 mg/dL), leaves (170.66 ± 2.3 mg/dL) and seeds (142 ± 8.7 mg/dL) when compared with control diabetic group (257.7 ± 6.7 mg/dL). It is concluded that methanolic extract of all parts possess significant anti-diabetic activity which is due to the presence of phytochemicals, i.e. alkaloids, flavonoids, phenols, saponins, tannins and it can be further evaluated for the mechanism involved. (author)

Synthesis of N-(Methoxycarbonylthienylmethylthioureas and Evaluation of Their Interaction with Inducible and Neuronal Nitric Oxide Synthase

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Michael D. Threadgill

2010-04-01

Full Text Available Two isomeric N-(methoxycarbonylthienylmethylthioureas were synthesised by a sequence of radical bromination of methylthiophenecarboxylic esters, substitution with trifluoroacetamide anion, deprotection, formation of the corresponding isothiocyanates and addition of ammonia. The interaction of these new thiophene-based thioureas with inducible and neuronal nitric oxide synthase was evaluauted. These novel thienylmethylthioureas stimulated the activity of inducible Nitric Oxide Synthase (iNOS.

Identificación de defensas inducibles a áfidos en cebadas pre-comerciales

OpenAIRE

Caridad, Alejandro; Saldúa, Vilma Luciana; Castro, Ana María

2018-01-01

Las plantas tienen la capacidad de adaptarse a situaciones de estrés mediante la expresión de genes implicados en mecanismos de defensa, que pueden ser constitutivos o inducibles, dependiendo si se expresan permanentemente o no. Detrás de la regulación de estos mecanismos se encuentran las hormonas, moléculas señalizadoras que comunican los distintos tejidos de la planta entre sí. Ante el ataque de insectos, el Acido Jasmónico (AJ) y el Acido Salicílico (AS) juegan un papel preponderante en l...

La aplicación privada del derecho antitrust y la indemnización de los daños derivados de ilícitos contra la libre competencia II Parte: La trasgresión de las normas de libre competencia como fundamento de la responsabilidad civil.

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Ingrid Soraya Ortiz Baquero

2008-06-01

Full Text Available El presente estudio tuvo como origen la investigación realizada sobre ¨La prohibición de los acuerdos restrictivos de la competencia y la valoración de las cláusulas de exclusividad en los regímenes de libre competencia europeo, español y colombiano¨, cuya primera y segunda parte se encuentran publicadas en esta revista. En razón de lo anterior, existen entre los dos estudios y sus publicaciones derivadas algunos puntos en común, teniendo en todo caso el presente trabajo adiciones de carácter complementario y una orientación diferente. El artículo que ahora se presenta pretende descubrir y destacar los relaciones entre el Derecho de Daños y el Derecho Anti trust, para lo cual se ha estimado necesario dividir la materia en dos partes: una primera parte presenta la evolución de los sistemas de aplicación de las normas de libre competencia, haciendo especial énfasis en proceso de privatización, para luego ahondar en una segunda parte, -que será publicado en forma independiente- el tema de la responsabilidad civil derivada de los ilícitos anti trust.

Los modelos de explotación petrolera de Ecuador y de Colombia: Un análisis desde el extractivismo y el neoextractivismo (segunda parte

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Luis Hernando Portillo Riascos

2015-07-01

Full Text Available En la primera parte de este trabajo se describieron los elementos conceptuales alrededor de los dos tipos o estilos de extractivismo. A la vez, se realizó una exposición de los principales cambios en el marco regulatorio del sector petrolero en los dos países analizados: Ecuador y Colombia. La segunda parte, que aquí se presenta, tiene como objetivo, hacer una revisión empírica de los dos modelos de explotación petrolera. En el análisis cuantitativo se encontró diferencias importantes en la evolución del sector petrolero de los dos países. En el caso ecuatoriano, el Estado fue capaz de desarrollar una política activa centrada en capturar una mayor parte de la renta petrolera. En Colombia, por su parte, se estructuró un marco regulatorio orientado a la atracción de capital, que en un contexto de subida de los precios, hizo posible un incremento significativo de la producción petrolera. Ahora bien, haciendo la comparación de los referentes conceptuales en torno a los dos tipos de extractivismo y la evolución de la dinámica productiva y fiscal, las divergencias ya no son tan evidentes.

Segunda Parte Bases para la Orientación de una Campaña de Reforestación en el Departamento

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Roldan Julio

1955-06-01

Full Text Available Conocida a grandes rasgos la historia sobre lo que se ha realizado en materia de fomento y defensa forestal, conviene, para la correcta orientación de una campaña efectiva en el Departamento, tener en cuenta las consideraciones siguientes: 1-La gravedad y extensión del problema, que implica la necesidad de acometer labores en varios frentes, para que la acción sea simultánea en toda el área Departamental. 2-La falta de conciencia pública en lo referente al papel que juegan los montes y arbolados en la economía general. 3-La ignorancia total por parte de los agricultores, de los sistemas racionales para explotación de bosques y el desconocimiento de los más elementales métodos de plantación y manejo de especies forestales, fruto del poco interés que ha despertado esta actividad, confiada hasta hoya la naturaleza, y, 4-La falta de experiencia en el personal técnico nacional y extranjero, sobre el comportamiento de las especies forestales nativas, al reducirlas de su vida salvaje a los tratamientos comunes en selvicultura y la muy poca experiencia, sobre las especies foráneas aclimatadas, respecto a los resultados finales de un cultivo extensivo.

Evaluation of N-acetylcysteine for the prevention of contrast-induced nephropathy

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Sara K. Richter

2015-06-01

Full Text Available Background: Contrast-induced nephropathy (CIN remains a leading cause of acute renal failure in hospitalized patients. N-Acetylcysteine has been studied previously for the prevention of CIN, resulting in mixed findings. Objective: The objective of this study was to determine the impact of N-acetylcysteine on the development of CIN in order to guide its use at community, teaching hospitals. Methods: Patients admitted between January 1 and December 31, 2011, receiving intravenous radiocontrast dye were included if they were compliant with two or more of the following conditions: baseline serum creatinine >1.2 mg/dL or estimated creatinine clearance <50 mL/min, age ≥75 years, diabetes mellitus, heart failure, or hypertension. The primary outcome was the difference in the proportion of patients in each group (N-acetylcysteine or no N-acetylcysteine who developed CIN, which was defined as a ≥0.5 mg/dL increase in serum creatinine or a ≥25% increase in serum creatinine within 12–96 hours post-exposure to contrast. Results: A total of 302 patients were included, 151 who received N-acetylcysteine and 151 who did not receive N-acetylcysteine. Patients who received N-acetylcysteine had significantly worse renal function at baseline than those who did not receive N-acetylcysteine (mean pre-contrast serum creatinine, 1.41 vs. 0.95 mg/dL, p<0.0001. A lower proportion of patients developing CIN was observed between those who received N-acetylcysteine and those who did not receive N-acetylcysteine (10.2% vs. 21.8%, p=0.0428. Conclusions: The use of N-acetylcysteine was likely associated with a reduced incidence of CIN in patients at risk for CIN development. Based on these results, hospitals may benefit from the development of a protocol to guide the appropriate use of N-acetylcysteine.

Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades

DEFF Research Database (Denmark)

Bragstad, Karoline; Martel, Cyril; Thomsen, Joakim S.

2011-01-01

Please cite this paper as: Bragstad et al. (2010) Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades. Influenza and Other Respiratory Viruses 5(1), 13-23. Background Alternative influenza vaccines...... and vaccine production forms are needed as the conventional protein vaccines do not induce broad cross-reactivity against drifted strains. Furthermore, fast vaccine production is especially important in a pandemic situation, and broader vaccine reactivity would diminish the need for frequent change...... in the vaccine formulations. Objective In this study, we compared the ability of pandemic influenza DNA vaccines to induce immunity against distantly related strains within a subtype with the immunity induced by conventional trivalent protein vaccines against homologous virus challenge. Methods Ferrets were...

Condicionantes económicos de la adopción de una innovación por parte del consumidor: análisis de la compra de servicios online

Directory of Open Access Journals (Sweden)

Alicia Izquierdo Yusta

2010-04-01

Full Text Available Este trabajo analiza el proceso de adopción de una innovación concreta por parte del consumidor final –en este caso, el uso y la adopción de Internet como canal de información y de compra– en la adquisición de un servicio. En concreto, se considera un servicio turístico de características muy particulares, como es la reserva de una pernoctación hotelera. La elección de este producto intangible resulta una gran contribución a la literatura relevante, no solo por la escasez de trabajos previos que hayan analizado este tipo de servicios, sino también por la importancia clave que el sector turístico posee en el ámbito geográfico donde el estudio se ha llevado a cabo. Para ello, tomando como base el modelo TAM, se ha tratado de analizar la influencia de ciertos factores económicos como son las señales de calidad y la confianza sobre las intenciones de compra. Los resultados obtenidos utilizando una muestra de 759 internautas que, siendo turistas potenciales no han adquirido el servicio, han puesto de manifiesto la importancia que tiene en las intenciones de compra del consumidor las normas subjetivas, la utilidad percibida, la confianza hacia el sitio web y las señales emitidas por las empresas para mitigar las asimetrías de información. De este trabajo se desprenden interesantes conclusiones que contribuyen a una mejor introducción y gestión de Internet como canal de información y venta por parte de las empresas.

Electrically active induced energy levels and metastability of B and N vacancy-complexes in 4H-SiC.

Science.gov (United States)

Igumbor, E; Olaniyan, O; Mapasha, R E; Danga, H T; Omotoso, E; Meyer, W E

2018-05-10

Electrically active induced energy levels in semiconductor devices could be beneficial to the discovery of an enhanced p or n-type semiconductor. Nitrogen (N) implanted into 4H-SiC is a high energy process that produced high defect concentrations which could be removed during dopant activation annealing. On the other hand, boron (B) substituted for silicon in SiC causes a reduction in the number of defects. This scenario leads to a decrease in the dielectric properties and induced deep donor and shallow acceptor levels. Complexes formed by the N, such as the nitrogen-vacancy centre, have been reported to play a significant role in the application of quantum bits. In this paper, results of charge states thermodynamic transition level of the N and B vacancy-complexes in 4H-SiC are presented. We explore complexes where substitutional N[Formula: see text]/N[Formula: see text] or B[Formula: see text]/B[Formula: see text] sits near a Si (V[Formula: see text]) or C (V[Formula: see text]) vacancy to form vacancy-complexes (N[Formula: see text]V[Formula: see text], N[Formula: see text]V[Formula: see text], N[Formula: see text]V[Formula: see text], N[Formula: see text]V[Formula: see text], B[Formula: see text]V[Formula: see text], B[Formula: see text]V[Formula: see text], B[Formula: see text]V[Formula: see text] and B[Formula: see text]V[Formula: see text]). The energies of formation of the N related vacancy-complexes showed the N[Formula: see text]V[Formula: see text] to be energetically stable close to the valence band maximum in its double positive charge state. The N[Formula: see text]V[Formula: see text] is more energetically stable in the double negative charge state close to the conduction band minimum. The N[Formula: see text]V[Formula: see text] on the other hand, induced double donor level and the N[Formula: see text]V[Formula: see text] induced a double acceptor level. For B related complexes, the B[Formula: see text]V[Formula: see text] and B[Formula: see text

Antioxidation, anti-inflammation and anti-apoptosis by paeonol in LPS/d-GalN-induced acute liver failure in mice.

Science.gov (United States)

Gong, Xiaobao; Yang, You; Huang, Ligua; Zhang, Qingyan; Wan, Rong-Zhen; Zhang, Peng; Zhang, Baoshun

2017-05-01

To evaluate the hepatoprotective effects and potential mechanisms of paeonol (Pae) against acute liver failure (ALF) induced by lipopolysaccharide (LPS)/d-galactosamine (d-GalN) in mice, we examined anti-oxidative, anti-inflammatory and anti-apoptotic activities of Pae. We found that Pae pretreatment markedly reduced the activities of alanine transaminase and aspartate transaminase as well as the histopathological changes induced by LPS/d-GalN. Catalase, glutathione and superoxide dismutase activities increased and reactive oxygen species activity decreased after Pae treatment compared with LPS/d-GalN treatment. Pretreatment with Pae also significantly inhibited the expression levels of iNOS, nitric oxide (NO), COX-2 and prostaglandin E 2 (PGE 2 ). In addition, Pae administration prevented the phosphorylated expression of IκB kinase, inhibitor kappa B in the nuclear factor-kappa B (NF-κB) signaling pathway, and suppressed the phosphorylated expression of extracellular signal-regulated kinase (ERK), c-jun-N-terminal kinase and p38 in the MAPK signaling pathway. Pretreatment with Pae also inhibited hepatocyte apoptosis by reducing the expression of caspases 3, 8, 9, and Bax, and increasing Bcl-2. In total, protective effects of Pae against LPS/d-GalN-induced ALF in mice are attributed to its antioxidative effect, inflammatory suppression in NF-κB and MARK signaling pathways, and inhibition of hepatocyte apoptosis inhibition. Therefore, Pae can be a potential therapeutic agent in attenuating LPS/d-GalN-induced ALF in the future. Copyright © 2017. Published by Elsevier B.V.

Strong Depletion in Hybrid Perovskite p-n Junctions Induced by Local Electronic Doping.

Science.gov (United States)

Ou, Qingdong; Zhang, Yupeng; Wang, Ziyu; Yuwono, Jodie A; Wang, Rongbin; Dai, Zhigao; Li, Wei; Zheng, Changxi; Xu, Zai-Quan; Qi, Xiang; Duhm, Steffen; Medhekar, Nikhil V; Zhang, Han; Bao, Qiaoliang

2018-04-01

A semiconductor p-n junction typically has a doping-induced carrier depletion region, where the doping level positively correlates with the built-in potential and negatively correlates with the depletion layer width. In conventional bulk and atomically thin junctions, this correlation challenges the synergy of the internal field and its spatial extent in carrier generation/transport. Organic-inorganic hybrid perovskites, a class of crystalline ionic semiconductors, are promising alternatives because of their direct badgap, long diffusion length, and large dielectric constant. Here, strong depletion in a lateral p-n junction induced by local electronic doping at the surface of individual CH 3 NH 3 PbI 3 perovskite nanosheets is reported. Unlike conventional surface doping with a weak van der Waals adsorption, covalent bonding and hydrogen bonding between a MoO 3 dopant and the perovskite are theoretically predicted and experimentally verified. The strong hybridization-induced electronic coupling leads to an enhanced built-in electric field. The large electric permittivity arising from the ionic polarizability further contributes to the formation of an unusually broad depletion region up to 10 µm in the junction. Under visible optical excitation without electrical bias, the lateral diode demonstrates unprecedented photovoltaic conversion with an external quantum efficiency of 3.93% and a photodetection responsivity of 1.42 A W -1 . © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Correlation of proton irradiation induced threshold voltage shifts to deep level traps in AlGaN/GaN heterostructures

Science.gov (United States)

Zhang, Z.; Cardwell, D.; Sasikumar, A.; Kyle, E. C. H.; Chen, J.; Zhang, E. X.; Fleetwood, D. M.; Schrimpf, R. D.; Speck, J. S.; Arehart, A. R.; Ringel, S. A.

2016-04-01

The impact of proton irradiation on the threshold voltage (VT) of AlGaN/GaN heterostructures is systematically investigated to enhance the understanding of a primary component of the degradation of irradiated high electron mobility transistors. The value of VT was found to increase monotonically as a function of 1.8 MeV proton fluence in a sub-linear manner reaching 0.63 V at a fluence of 1 × 1014 cm-2. Silvaco Atlas simulations of VT shifts caused by GaN buffer traps using experimentally measured introduction rates, and energy levels closely match the experimental results. Different buffer designs lead to different VT dependences on proton irradiation, confirming that deep, acceptor-like defects in the GaN buffer are primarily responsible for the observed VT shifts. The proton irradiation induced VT shifts are found to depend on the barrier thickness in a linear fashion; thus, scaling the barrier thickness could be an effective way to reduce such degradation.

Variación de la energía libre de Gibbs de la caolinita en función de la cristalinidad y tamaño de partícula

Directory of Open Access Journals (Sweden)

La Iglesia, A.

1989-12-01

Full Text Available The effect of grinding on crystallinity, particle size and solubility of two samples of kaolinite was studied. The standard Gibbs free energies of formation of different ground samples were calculated from solubility measurements, and show a direct relationship between Gibbs free energy and particle size-crystallinity variation. Values of -3752.2 and -3776.4 KJ/mol. were determinated for ΔGºl (am and ΔGºl (crys of kaolinite, respectively. A new thermodinamic equation that relates ΔGºl to particle size is proposed. This equation can probably be extended to clay mineals.Se estudia el efecto de la molienda prolongada sobre la cristalinidad, tamaño de partícula y solubilidad de dos muestras de caolinita. Se ha calculado la energía libre estandar de formación del mineral a partir de medidas de solubilidad, encontrando una relación directa entre ΔGºl, y las variaciones de tamaño de partícula y cristalinidad de las muestras. Por extrapolación, se han obtenido los valores de -3752,0 y -3776,4 KJ/mol. para ΔGºl caolinita amorfa y cristalina. Se propone una ecuación termodinámica que relaciona ΔGºl y el tamaño de partícula de la caolinita; esta ecuación puede aplicarse también a otros minerales de la arcilla.

La resolución de conflictos en el aula como parte del proceso de autonomía

OpenAIRE

Díaz, María

2005-01-01

El desarrollo de la autonomía emocional y la resolución de conflictos son objetivos prioritarios para la convivencia y el crecimiento personal. A través de una observación sistemática y un modelo log-linear, este estudio muestra el bajo nivel de autonomía en los primeros ciclos de la etapa de Educación Primaria, una gran dificultad por parte de los niños para resolver conflictos y una enorme dependencia emocional y cognitiva respecto al adulto. Esto puede continuar en etapas posteriores, por ...

La admisión de pruebas de oficio en el sistema penal acusatorio garantista y la vulneración del principio de imparcialidad del juzgador e igualdad de las partes establecidas en la constitución

OpenAIRE

Challco Gamero, Fredy

2014-01-01

La- investigación: “La admisión de pruebas de oficio en el sistema penal acusatorio garantista y la vulneración del principio de imparcialidad del juzgador e igualdad de las partes, establecidas en la constitución" plantea como objetivo: determinar si la admisión de pruebas de oficio en el sistema procesal penal acusatorio garantista adversativo, vulnerara derechos fundamentales del debido proceso establecido en la Constitución. Es un estudio de diseño explicativo causal, es decir, el nivel n...

Simulación de la fluencia en caliente de un acero microaleado con un contenido medio de carbono. I parte. Aproximación teórica

Directory of Open Access Journals (Sweden)

Cabrera, J. M.

1997-04-01

Full Text Available The constitutive equations to model the hot flow behaviour of metallic materials in general, and of microalloyed steels in particular (see part 2 of this work are established in this work. Special emphasis is done on the dynamic softening mechanisms, i.e., dynamic recovery and recrystallization phenomena. The equations developed are physic-based, not empirical, and the modeling allows an easy implementation in an analysis by numerical methods. The resulting equations are even able to predict the final grain size.

En la presente revisión se plantean las ecuaciones constitutivas necesarias para efectuar la modelización de la fluencia en caliente de materiales metálicos y, en particular, de un acero microaleado (Véase la II parte de este trabajo. Se hace especial hincapié en la simulación de los fenómenos de restauración y recristalización dinámica. Las ecuaciones propuestas son de base física, no empírica, y el modelo resultante es relativamente sencillo de utilizar y de implementar en un análisis por métodos numéricos. El estudio no queda circunscrito al comportamiento a fluencia sino que es capaz de predecir el tamaño de grano final.

Shock-Assisted Superficial Hexagonal-to-Cubic Phase Transition in GaN/Sapphire Interface Induced by Using Ultra-violet Laser Lift-Of Techniques

International Nuclear Information System (INIS)

Wei-Hua, Chen; Xiao-Dong, Hu; Xiang-Ning, Kang; Xu-Rong, Zhou; Xiao-Min, Zhang; Tong-Jun, Yu; Zhi-Jian, Yang; Ke, Xu; Guo-Yi, Zhang; Xu-Dong, Shan; Li-Ping, You

2009-01-01

Ultra-violet (KrF excimer laser, λ = 248 nm) laser lift-of (LLO) techniques have been operated to the GaN/sapphire structure to separate GaN from the sapphire substrate. Hexagonal to cubic phase transformation induced by the ultra-violet laser lift-of (UV-LLO) has been characterized by micro-Raman spectroscopy, micro-photoluminescence, along with high-resolution transmission electron microscopy (HRTEM). HRTEM indicates that UV-LLO induced phase transition takes place above the LLO interface, without phase transition under the LLO interface. The formed cubic GaN often exists as nanocrystal grains attaching on the bulk hexagonal GaN. The half-loop-cluster-like UV-LLO interface indicates that the LLO-induced shock waves has generated and played an assistant role in the decomposition of the hexagonal GaN and in the formation of cubic GaN grains at the LLO surface

Instability of expanded simple tandem repeats is induced in cell culture by a variety of agents: N-Nitroso-N-ethylurea, benzo(a)pyrene, etoposide and okadaic acid

Energy Technology Data Exchange (ETDEWEB)

Polyzos, Aris [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Parfett, Craig [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Healy, Caroline [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Douglas, George R. [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada); Yauk, Carole L. [Environmental Health Centre, Environmental and occupational Toxicology Division, Health Canada, Tunney' s Pasture, P.L. 0803A, Ottawa, Ont., K1A 0L2 (Canada)]. E-mail: Carole_Yauk@hc-sc.gc.ca

2006-06-25

Expanded simple tandem repeat (ESTR) sequences have proven useful biomarkers to detect genotoxicity in vivo. Their high sensitivity has been used to assess environmentally relevant doses of mutagens such as ionizing radiation, DNA alkylating agents and airborne particulate pollution, for germline mutations in mouse assays. The mutagenic response involves size alteration of these ESTR loci induced by agents causing a variety of cellular damage. The mechanistic aspects of this induced instability remain unclear and have not been studied in detail. Mechanistic knowledge is important to help understand the relevance of increased ESTR mutation frequencies. In this study, we applied a murine cell culture system to examine induced response to four agents exhibiting different modes of toxic action including: N-nitroso-N-ethylurea (ENU), benzo(a)pyrene (BaP), okadaic acid and etoposide at slightly sub-toxic levels. We used single-molecule-polymerase chain reaction (SM-PCR) to assess the relative mutant frequency after 4-week chemical treatments at the Ms6-hm ESTR sequence of cultured C3H/10T1/2 cells (a mouse embryonic cell line). Increased mutation was observed with both 0.64 mM ENU (1.95-fold increase, P < 0.0001), 1 {mu}M benzo(a)pyrene (1.87-fold increase, P = 0.0006) and 3 nM etoposide (1.89-fold increase, P = 0.0003). The putative ESTR mutagen okadaic acid (1.27-fold increase, P = 0.2289), administered at 0.5 nM, did not affect the C3H/10T1/2 Ms6-hm locus. Therefore, agents inducing small and bulky adducts, and indirectly causing strand breaks through inhibition of topoisomerase, caused similar induction of instability at an ESTR locus at matched toxicities. As size spectra for induced mutations were identical, the data indicate that although these chemicals exhibit distinct modes of action, a similar indirect process is influencing ESTR instability. In contrast, a potent tumour promoter that is a kinase inhibitor does not contribute to induced ESTR instability in

Instability of expanded simple tandem repeats is induced in cell culture by a variety of agents: N-Nitroso-N-ethylurea, benzo(a)pyrene, etoposide and okadaic acid

International Nuclear Information System (INIS)

Polyzos, Aris; Parfett, Craig; Healy, Caroline; Douglas, George R.; Yauk, Carole L.

2006-01-01

Expanded simple tandem repeat (ESTR) sequences have proven useful biomarkers to detect genotoxicity in vivo. Their high sensitivity has been used to assess environmentally relevant doses of mutagens such as ionizing radiation, DNA alkylating agents and airborne particulate pollution, for germline mutations in mouse assays. The mutagenic response involves size alteration of these ESTR loci induced by agents causing a variety of cellular damage. The mechanistic aspects of this induced instability remain unclear and have not been studied in detail. Mechanistic knowledge is important to help understand the relevance of increased ESTR mutation frequencies. In this study, we applied a murine cell culture system to examine induced response to four agents exhibiting different modes of toxic action including: N-nitroso-N-ethylurea (ENU), benzo(a)pyrene (BaP), okadaic acid and etoposide at slightly sub-toxic levels. We used single-molecule-polymerase chain reaction (SM-PCR) to assess the relative mutant frequency after 4-week chemical treatments at the Ms6-hm ESTR sequence of cultured C3H/10T1/2 cells (a mouse embryonic cell line). Increased mutation was observed with both 0.64 mM ENU (1.95-fold increase, P < 0.0001), 1 μM benzo(a)pyrene (1.87-fold increase, P = 0.0006) and 3 nM etoposide (1.89-fold increase, P = 0.0003). The putative ESTR mutagen okadaic acid (1.27-fold increase, P = 0.2289), administered at 0.5 nM, did not affect the C3H/10T1/2 Ms6-hm locus. Therefore, agents inducing small and bulky adducts, and indirectly causing strand breaks through inhibition of topoisomerase, caused similar induction of instability at an ESTR locus at matched toxicities. As size spectra for induced mutations were identical, the data indicate that although these chemicals exhibit distinct modes of action, a similar indirect process is influencing ESTR instability. In contrast, a potent tumour promoter that is a kinase inhibitor does not contribute to induced ESTR instability in cell

Determinantes del retraso de la interrupción voluntaria del embarazo Determinants of induced abortion delay

OpenAIRE

Laia Font-Ribera; Glòria Pérez; Albert Espelt; Joaquin Salvador; Carme Borrell

2009-01-01

Antecedentes: El momento de la gestación en que se induce una interrupción voluntaria del embarazo (IVE) determina el método, el riesgo de complicaciones y el coste económico de la intervención. El objetivo de nuestro estudio fue describir los determinantes del retraso de la IVE hasta el segundo trimestre de gestación en Barcelona. Métodos: Estudio transversal de las IVE por motivos de salud física o mental de la mujer (Barcelona, 2004-2005; N=9.175). El registro de IVE de la ciudad proporcio...

PKC phosphorylates residues in the N-terminal of the DA transporter to regulate amphetamine-induced DA efflux.

Science.gov (United States)

Wang, Qiang; Bubula, Nancy; Brown, Jason; Wang, Yunliang; Kondev, Veronika; Vezina, Paul

2016-05-27

The DA transporter (DAT), a phosphoprotein, controls extracellular dopamine (DA) levels in the central nervous system through transport or reverse transport (efflux). Multiple lines of evidence support the claim that PKC significantly contributes to amphetamine-induced DA efflux. Other signaling pathways, involving CaMKII and ERK, have also been shown to regulate DAT mediated efflux. Here we assessed the contribution of putative PKC residues (S4, S7, S13) in the N-terminal of the DAT to amphetamine-induced DA efflux by transfecting DATs containing different serine to alanine (S-A) point mutations into DA pre-loaded HEK-293 cells and incubating these cells in amphetamine (2μM). The effects of a S-A mutation at the non-PKC residue S12 and a threonine to alanine (T-A) mutation at the ERK T53 residue were also assessed for comparison. WT-DATs were used as controls. In an initial experiment, we confirmed that inhibiting PKC with Go6976 (130nM) significantly reduced amphetamine-induced DA efflux. In subsequent experiments, cells transfected with the S4A, S12A, S13A, T53A and S4,7,13A mutants showed a reduction in amphetamine-induced DA efflux similar to that observed with Go6976. Interestingly, cells transfected with the S7A mutant, identified by some as a PKC-PKA residue, showed unperturbed WT-DAT levels of amphetamine-induced DA efflux. These results indicate that phosphorylation by PKC of select residues in the DAT N-terminal can regulate amphetamine-induced efflux. PKC can act either independently or in concert with other kinases such as ERK to produce this effect. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The effects of antiepileptic inducers in neuropsychopharmacology, a neglected issue. Part II: Pharmacological issues and further understanding.

Science.gov (United States)

de Leon, Jose

2015-01-01

The literature on inducers in epilepsy and bipolar disorder is seriously contaminated by false negative findings. Part II of this comprehensive review on antiepileptic drug (AED) inducers provides clinicians with further educational material about the complexity of interpreting AED drug-drug interactions. The basic pharmacology of induction is reviewed including the cytochrome P450 (CYP) isoenzymes, the Uridine Diphosphate Glucuronosyltransferases (UGTs), and P-glycoprotein (P-gp). CYP2B6 and CYP3A4 are very sensitive to induction. CYP1A2 is moderately sensitive while CYP2C9 and CYP2C19 are only mildly sensitive. CYP2D6 cannot be induced by medications. Induction of UGT and P-gp are poorly understood. The induction of metabolic enzymes such as CYPs and UGTs, and transporters such as P-gp, implies that the amount of these proteins increases when they are induced; this is almost always explained by increasing synthesis mediated by the so-called nuclear receptors (constitutive androstane, estrogen, glucocorticoid receptors and pregnaneX receptors). Although parti provides correction factors for AEDs, extrapolation from an average to an individual patient may be influenced by administration route, absence of metabolic enzyme for genetic reasons, and presence of inhibitors or other inducers. AED pharmacodynamic DDIs may also be important. Six patients with extreme sensitivity to AED inductive effects are described. Copyright © 2014 SEP y SEPB. Published by Elsevier España. All rights reserved.

Collision induced dissociation of protonated N-nitrosodimethylamine by ion trap mass spectrometry: Ultimate carcinogens in gas phase

Science.gov (United States)

Kulikova, Natalia; Baker, Michael; Gabryelski, Wojciech

2009-12-01

Collision induced dissociation of protonated N-nitrosodimethylamine (NDMA) and isotopically labeled N-nitrosodimethyl-d6-amine (NDMA-d6) was investigated by sequential ion trap mass spectrometry to establish mechanisms of gas phase reactions leading to intriguing products of this potent carcinogen. The fragmentation of (NDMA + H+) occurs via two dissociation pathways. In the alkylation pathway, homolytic cleavage of the N-O bond of N-dimethyl, N'-hydroxydiazenium ion generates N-dimethyldiazenium distonic ion which reacts further by a CH3 radical loss to form methanediazonium ion. Both methanediazonium ion and its precursor are involved in ion/molecule reactions. Methanediazonium ion showed to be capable of methylating water and methanol molecules in the gas phase of the ion trap and N-dimethyldiazenium distonic ion showed to abstract a hydrogen atom from a solvent molecule. In the denitrosation pathway, a tautomerization of N-dimethyl, N'-hydroxydiazenium ion to N-nitrosodimethylammonium intermediate ion results in radical cleavage of the N-N bond of the intermediate ion to form N-dimethylaminium radical cation which reacts further through [alpha]-cleavage to generate N-methylmethylenimmonium ion. Although the reactions of NDMA in the gas phase are different to those for enzymatic conversion of NDMA in biological systems, each activation method generates the same products. We will show that collision induced dissociation of N-nitrosodiethylamine (NDEA) and N-nitrosodipropylamine (NDPA) is also a feasible approach to gain information on formation, stability, and reactivity of alkylating agents originating from NDEA and NDPA. Investigating such biologically relevant, but highly reactive intermediates in the condensed phase is hampered by the short life-times of these transient species.

The influence of water stress on biomass and N accumulation, N partitioning between above and below ground parts and on N rhizodeposition during reproductive growth of pea (Pisum sativum L.)

DEFF Research Database (Denmark)

Mahieu, S.; Germont, Florent; Aveline, A.

2009-01-01

are estimated. Moreover, grain legume crops are largely influenced by water stress while the world area exposed to drought periods may increase in the coming years due to global warming. This work aims to quantify biomass and N accumulation, N partitioning between above and below ground parts and N...... rhizodeposition by a pea (Pisum sativum L.) when influenced by water stress. In a controlled environment, pea plants were exposed to a severe drought or not stressed, either at flowering or during pod filling. N rhizodeposition was measured using the split root method and plants were harvested at the end...... of flowering (59 days after sowing, DAS 59), at the end of the drought period applied during pod filling (DAS 74) and at maturity (DAS 101). Water stress strongly affected pea dry weight and N accumulation. In both stressed treatments, nodule biomass and N content were reduced by about 65% in the absence...

Preventive effect of Oenothera rosea on N-methyl-N-nitrosourea- (NMU induced gastric cancer in rats

Directory of Open Access Journals (Sweden)

Almora-Pinedo Y

2017-12-01

Full Text Available Yuan Almora-Pinedo,1 Jorge Arroyo-Acevedo,2 Oscar Herrera-Calderon,3 Víctor Chumpitaz-Cerrate,4 Renán Hañari-Quispe,5 Aldo Tinco-Jayo,6 Cesar Franco-Quino,4 Linder Figueroa-Salvador7 1Department of Pharmacy, Hospital Nacional Hipólito Unanue, Lima, 2Laboratory of Experimental Pharmacology, Faculty of Medicine, Universidad Nacional Mayor de San Marcos, Lima, 3Faculty of Pharmacy and Biochemistry, Universidad Nacional San Luis Gonzaga de Ica, Ica, 4Laboratory of Physiology and Pharmacology, Faculty of Dentistry, Universidad Nacional Mayor de San Marcos, Lima, 5Laboratory of Animal Physiology, Universidad Andina Néstor Cáceres Velasquez, Puno, 6Academic Department of Human Medicine, School of Pharmacy and Biochemistry, Universidad Nacional San Cristóbal de Huamanga, Ayacucho, 7School of Medicine, Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas, Lima, Peru Background: Currently, gastric cancer (GC is considered a public health problem worldwide. Using medicinal plants for the prevention of chronic diseases such as cancer constitutes new alternatives in traditional medicine. Oenothera rosea (OR could be an option, but it needs to be evaluated. Aim: The main objective of this study was to evaluate the protective effect of OR extract on N-methyl-N-nitrosourea (NMU-induced GC in rats. Methods: In total, 80 male Holtzman rats were randomized into five groups. Group A received the saline solution (5mL/kg, group B received NMU 500 μg/kg (cancer inductor by oral administration for 16 weeks, and groups C, D, and E were treated with OR extract (100, 200, and 300 mg/kg, respectively and NMU in order to evaluate the preventive effect on cancer induced by NMU for 16 weeks. Blood and histological samples of stomachs were collected to determine histopathological, biochemical, and hematological parameters between different experimental groups. Results: Groups C, D, and E presented less histopathological changes such as anaplastic and

¿Los estudiantes de educación básica y media son víctimas de maltrato por parte de sus profesores?

Directory of Open Access Journals (Sweden)

Elvia Sánchez-Jiménez

2014-01-01

Full Text Available El objetivo del presente artículo es caracterizar el nivel de victimi - zación de 3.226 estudiantes de educación básica y media, de grados sexto a once, de colegios oficiales de la ciudad de Bogotá, desde su percepción de las manifestaciones de maltrato y / o agresión por parte de sus profesores. El instrumento “Maltrato a estudiante por parte del profesor” consta de 20 ítems de respuesta politómica y en él se describe la frecuencia con la que los estudiantes son víctimas de las manifestaciones de violencia y / o agresión evaluadas. Se presentan los resultados del análisis estadístico descriptivo de los datos usando el modelo de teoría de respuesta al ítem de crédito parcial generalizado. Los resultados obtenidos en esta investigación señalan que, aunque es poco frecuente, los estudiantes de educación básica y media son víctimas de maltrato por parte de algunos de sus profesores.

Fuente de Alimentación para los Imanes Superconductores del Acelerador de Partículas Europeo XFEL

OpenAIRE

García, O.; Francés, A.; Fernández, J. M.; Varela, Pablo; Catalanotto, Giuseppe; Alou Cervera, Pedro; Oliver Ramírez, Jesús Angel; Asensi Orosa, Rafael; Prieto López, Roberto; Uceda Antolín, Javier; Cobos Márquez, José Antonio

2013-01-01

En este artículo se presenta la fuente de alimentación que se está diseñando para alimentar los imanes superconductores del acelerador de partículas europeo XFEL que se está construyendo en Hamburgo, cuyas características le hacen el más avanzado del mundo. Un imán superconductor es una carga muy inductiva que debe ser controlada en corriente y que presenta una caída de tensión muy baja cuando está en modo superconductor. La fuente debe ser capaz de alimentar esta carga con una alta fiabilida...

Factores que influyen sobre la producción científica en Contabilidad en España: la opinión de los profesores universitarios de Contabilidad (II parte

Directory of Open Access Journals (Sweden)

Escobar-Pérez, Bernabé

2014-06-01

Full Text Available This paper is the second part of an article, the first part of which was published in REDC, 2013, nº3. The aim of this paper is to analyse the opinion of academics in the field of accounting about their research productivity and the factors that could explain the differences with respect to other areas. It is a cross-sectional study of the population of members of ASEPUC by means of surveys. The results show that the causes of the differences in research productivity are explained as: problems for delimiting the research in accounting, a lack of motivation due to rejected papers and non-compensated efforts, sparse incentives for researching, and a lack of methodological training, as well as the amount of time needed for dedication to teaching activities. Tenure, professional position, productivity and university size all influence the opinion concerning scientific productivity in accounting.Este trabajo es la segunda parte del publicado en la REDC, 2013, nº 3, e015, siendo su objetivo analizar la opinión del profesorado universitario en Contabilidad sobre su producción científica y las causas que pueden explicar su diferencia con respecto a otras áreas afines. Para ello, realizamos una encuesta, cuyos resultados ponen de manifiesto que las causas que permiten explicar la diferencia de la producción científica en Contabilidad con otras áreas afines son muy diversas, pudiéndose destacar entre ellas la dificultad para delimitar la investigación en Contabilidad, la desmotivación por los rechazos sufridos y el esfuerzo no recompensado, así como la falta de incentivos a la investigación, el tiempo dedicado a la docencia y la falta de formación metodológica. Asimismo, hemos constatado que tanto la edad, como el tamaño de la universidad de pertenencia, la categoría profesional del profesor y la posesión de tramos de investigación influyen en su opinión sobre la producción científica contable en España.

Aplicación de RT-Linux en el control de motores de pasos. Parte II; Appication of RT-Linux in the Control of Steps Motors. Part II

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Ernesto Duany Renté

2011-02-01

Full Text Available Este trabajo complementa al presentado anteriormente: "Aplicación de RT-Linux en el control de motoresde pasos. Primera parte", de manera que se puedan relacionar a las tareas de adquisición y control para laobtención de un sistema lo más exacto posible. Las técnicas empleadas son las de tiempo real aprovechandolas posibilidades del microkernel RT-Linux y los software libres contenidos en sistemas Unix/Linux. Lasseñales se obtienen mediante un conversor AD y mostradas en pantalla empleando el Gnuplot.  The work presented in this paper is a complement to the control and acquisition tasks which were explainedin "Application of RT-Linux in the Control of Steps Motors. First Part", so that those both real time taskscan be fully related in order to make the whole control system more accurate. The employed techniquesare those of Real Time Taking advantage of the possibilities of the micro kernel RT-Linux and the freesoftware distributed in the Unix/Linux operating systems. The signals are obtained by means of an ADconverter and are shown in screen using Gnuplot.

Estudio comparativo de la determinación del tamaño de partícula por dos métodos : tamizado en seco y disfracción láser

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Diana Míguez Carames

2011-05-01

Full Text Available El objetivo de este trabajo fue comparar el desempeño analítico de la tecnología de medición de tamaño de partícula por difracción láser con la técnica clásica de tamizado en seco para partículas superiores a 80 micras. Se utilizó arena como muestra de referencia interna. El procedimiento mecánico se realizó con equipo vibrador de tamices durante 15 minutos y batería de tamices estándar ASTM números 20, 40, 70 y 170. La determinación por difracción tri-laser, que implica hacer incidir tres haces de luz láser sobre la partícula, permite evaluar las dimensiones y realizar una distribución de tamaños generada por frecuencias de datos dispuestas en rangos. La muestra tamizada se reconstituyó uniendo sus porciones y se cuarteó por separador rotativo de alta exactitud y reproducibilidad. Una muestra representativa se suspendió en agua con agitación mecánica y los datos de las medidas se representaron gráficamente usando el software del equipo. Se realizaron 10 réplicas por cada método para evaluarlos estadísticamente mediante los métodos de los momentos y Falk y Ward. Se concluye que ambos clasifican la muestra de la mismaforma pero existen diferencias en los coeficientes de curtosis para las distribuciones de las poblaciones según una y otra técnicas.

Anticonvulsant effect of minocycline on pentylenetetrazole-induced seizure in mice: involvement of nitric oxide and N-methyl-D-aspartate receptor.

Science.gov (United States)

Amini-Khoei, Hossein; Kordjazy, Nastaran; Haj-Mirzaian, Arya; Amiri, Shayan; Haj-Mirzaian, Arvin; Shirzadian, Armin; Hasanvand, Amin; Balali-Dehkordi, Shima; Hassanipoor, Mahsa; Dehpour, Ahmad Reza

2018-03-20

Anticonvulsant effects of minocycline have been explored recently. This study was designed to examine the anticonvulsant effect of acute administration of minocycline on pentylenetetrazole (PTZ)-induced seizures in mouse considering the possible role of nitric oxide (NO)/NMDA pathway. We induced seizure using intravenous administration of PTZ. Our results showed that acute administration of minocycline increased the seizure threshold. Furthermore, co-administration of sub-effective doses of the non-selective nitric oxide synthase (NOS) inhibitor, L-NAME (10 mg/kg) and the neuronal NOS inhibitor, 7-nitroindazole (40 mg/kg) enhanced the anticonvulsant effect of sub-effective dose of minocycline (40 mg/kg). We found that inducible NOS inhibitor, aminoguanidine (100 mg/kg), had no effect on the anti-seizure effect of minocycline. Moreover, L-arginine (60 mg/kg), as a NOS substrate, reduced the anticonvulsant effect of minocycline. We also demonstrated that pretreatment with NMDA receptor antagonists, ketamine (0.5 mg/kg) and MK-801 (0.05 mg/kg) increased the anticonvulsant effect of sub-effective dose of minocycline. Results showed that minocycline significantly decreased the hippocampal nitrite level. Furthermore, co-administration of nNOS inhibitor like NMDA receptor antagonists augmented the effect of minocycline on the hippocampal nitrite level. In conclusion, we revealed that anticonvulsant effect of minocycline might be, at least in part, due to decline in constitutive hippocampal nitric oxide activity as well as inhibition of NMDA receptors.

¿Los estudiantes de educación básica y media son víctimas de maltrato por parte de sus profesores?

OpenAIRE

Elvia Sánchez-Jiménez; Edilberto Cepeda-Cuervo

2014-01-01

El objetivo del presente artículo es caracterizar el nivel de victimi - zación de 3.226 estudiantes de educación básica y media, de grados sexto a once, de colegios oficiales de la ciudad de Bogotá, desde su percepción de las manifestaciones de maltrato y / o agresión por parte de sus profesores. El instrumento “Maltrato a estudiante por parte del profesor” consta de 20 ítems de respuesta politómica y en él se describe la frecuencia con la que los estudiantes son víctimas de las manifestacion...

Adaptación española del "International Affective Picture System" (IAPS: tercera parte

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Javier Moltó

2013-10-01

Full Text Available Este trabajo proporciona los valores normativos españoles de las 358 imágenes que forman los conjuntos 15 a 20 del International Affective Picture System (IAPS. En este estudio participaron 811 estudiantes universitarios (521 mujeres que evaluaron las imágenes en las dimensiones emocionales de valencia, activación y dominancia. Las correlaciones entre las evaluaciones estadounidenses y las españolas en todas las dimensiones fueron altamente significativas y, como en Estados Unidos, la distribución de las imágenes en el espacio bidimensional afectivo definido por las dimensiones de valencia y activación adoptó la típica forma de boomerang. Los resultados confirmaron, asimismo, las diferencias de género encontradas en Estados Unidos en las evaluaciones de las imágenes aversivas. Estos resultados son totalmente consistentes con los obtenidos en la primera y segunda parte de la adaptación española, y demuestran que la estandarización del IAPS en nuestro país ha sido adecuada. Por último, se ratificaron las pequeñas diferencias transculturales encontradas en las evaluaciones de activación y dominancia: los españoles tendieron a asignar a las imágenes mayores puntuaciones en activación y menores en dominancia que los estadounidenses. Estos datos apoyan los estereotipos culturales de estos países y sugieren que el IAPS podría ser un indicador fiable de diferencias transculturales en la disposición emocional.

Antidiabetic activities of aqueous ethanol and n-butanol fraction of Moringa stenopetala leaves in streptozotocin-induced diabetic rats.

Science.gov (United States)

Toma, Alemayehu; Makonnen, Eyasu; Mekonnen, Yelamtsehay; Debella, Asfaw; Adisakwattana, Sirichai

2015-07-18

Moringa stenopetala has been used in traditional health systems to treat diabetes mellitus. The aim of this study was to investigate the antidiabetic activity of aqueous ethanol and n-butanol fraction of Moringa stenopetala leaves in streptozotocin (STZ) induced diabetic rats. The aqueous ethanol extract and n-butanol fraction of Moringa stenopetala leaves hydroalcoholic (500 mg/kg body weight) and metformin (150 mg/kg body weight) were administered to diabetic rats. Blood glucose, lipid profiles, liver and kidney function were examined after 14 days of experiment. Histopathological profile of the pancreas was also observed in diabetic rats at the end of study. An oral sucrose challenge test was also carried out to assess the post prandial effect of the extract. Oral administration of the aqueous ethanol and n-butanol extracts of Moringa stenopetala leaves (500 mg/kg body weight) and metformin (150 mg/kg) significantly reduced blood glucose level (PMoringa stenopetala leaves possess antihyperglycemic and antihyperlipidemic properties, and alleviate STZ-induced pancreatic damage in diabetic rats. The beneficial effects of plant material in inhibition of diabetes-induced complications are being investigated.

Evaluation of reactor induced (n,p) reactions for activation analysis of titanium in geological materials

Energy Technology Data Exchange (ETDEWEB)

Espinosa Garcia, R; Cohen, I M [Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

1984-05-01

The possibilities of reactor induced (n,p) reactions as a tool for neutron activation analysis of titanium in geological samples are discussed. The interference of calcium and scandium is experimentally evaluated. Results for Ti, Ca and Sc in GSP-1 and PCC-1 standard rocks are presented. Based on the experimental values, it is concluded that the /sup 47/Ti(n,p)/sup 47/Sc reaction is the most favourable for titanium determination. 11 refs.

Correlation of proton irradiation induced threshold voltage shifts to deep level traps in AlGaN/GaN heterostructures

Energy Technology Data Exchange (ETDEWEB)

Zhang, Z.; Cardwell, D.; Sasikumar, A.; Arehart, A. R.; Ringel, S. A., E-mail: ringel.5@osu.edu [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Kyle, E. C. H.; Speck, J. S. [Department of Materials, University of California, Santa Barbara, California 93106-5050 (United States); Chen, J.; Zhang, E. X.; Fleetwood, D. M.; Schrimpf, R. D. [Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235 (United States)

2016-04-28

The impact of proton irradiation on the threshold voltage (V{sub T}) of AlGaN/GaN heterostructures is systematically investigated to enhance the understanding of a primary component of the degradation of irradiated high electron mobility transistors. The value of V{sub T} was found to increase monotonically as a function of 1.8 MeV proton fluence in a sub-linear manner reaching 0.63 V at a fluence of 1 × 10{sup 14} cm{sup −2}. Silvaco Atlas simulations of V{sub T} shifts caused by GaN buffer traps using experimentally measured introduction rates, and energy levels closely match the experimental results. Different buffer designs lead to different V{sub T} dependences on proton irradiation, confirming that deep, acceptor-like defects in the GaN buffer are primarily responsible for the observed V{sub T} shifts. The proton irradiation induced V{sub T} shifts are found to depend on the barrier thickness in a linear fashion; thus, scaling the barrier thickness could be an effective way to reduce such degradation.

Correlation of proton irradiation induced threshold voltage shifts to deep level traps in AlGaN/GaN heterostructures

International Nuclear Information System (INIS)

Zhang, Z.; Cardwell, D.; Sasikumar, A.; Arehart, A. R.; Ringel, S. A.; Kyle, E. C. H.; Speck, J. S.; Chen, J.; Zhang, E. X.; Fleetwood, D. M.; Schrimpf, R. D.

2016-01-01

The impact of proton irradiation on the threshold voltage (V T ) of AlGaN/GaN heterostructures is systematically investigated to enhance the understanding of a primary component of the degradation of irradiated high electron mobility transistors. The value of V T was found to increase monotonically as a function of 1.8 MeV proton fluence in a sub-linear manner reaching 0.63 V at a fluence of 1 × 10 14  cm −2 . Silvaco Atlas simulations of V T shifts caused by GaN buffer traps using experimentally measured introduction rates, and energy levels closely match the experimental results. Different buffer designs lead to different V T dependences on proton irradiation, confirming that deep, acceptor-like defects in the GaN buffer are primarily responsible for the observed V T shifts. The proton irradiation induced V T shifts are found to depend on the barrier thickness in a linear fashion; thus, scaling the barrier thickness could be an effective way to reduce such degradation.

N-type polycrystalline silicon films formed on alumina by aluminium induced crystallization and overdoping

Energy Technology Data Exchange (ETDEWEB)

Tuezuen, O. [InESS, UMR 7163 CNRS-ULP, 23 rue du Loess, F-67037 Strasbourg (France)], E-mail: Ozge.Tuzun@iness.c-strasbourg.fr; Slaoui, A. [InESS, UMR 7163 CNRS-ULP, 23 rue du Loess, F-67037 Strasbourg (France); Gordon, I. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Focsa, A. [InESS, UMR 7163 CNRS-ULP, 23 rue du Loess, F-67037 Strasbourg (France); Ballutaud, D. [GEMaC-UMR 8635 CNRS, 1 place Aristide Briand, F-92195 Meudon (France); Beaucarne, G.; Poortmans, J. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

2008-08-30

In this work, we investigated the formation of n-type polysilicon films on alumina substrates by overdoping a p-type silicon layer obtained by aluminium induced crystallization of amorphous silicon (AIC), and subsequent epitaxy. The phosphorus doping of the AIC was carried out by thermal diffusion from a solid source. The structural quality of the n-type Si film was monitored by optical microscope and scanning electron microscope (SEM). The doping efficiency was determined by resistivity measurements and secondary ion mass spectroscopy (SIMS). The sheet resitivity changed from 2700{omega}/sq to 19.6{omega}/sq after thermal diffusion at 950 deg. C for 1h, indicating the overdoping effect. The SIMS profile carried out after the high temperature epitaxy exhibits a two steps phosphorus distribution, indicating the formation of an n{sup +}n structure.

Alkaloid fraction of Uncaria rhynchophylla protects against N-methyl-D-aspartate-induced apoptosis in rat hippocampal slices.

Science.gov (United States)

Lee, Jongseok; Son, Dongwook; Lee, Pyeongjae; Kim, Sun-Yeou; Kim, Hocheol; Kim, Chang-Ju; Lim, Eunhee

2003-09-04

Uncaria rhynchophylla is a medicinal herb which has sedative and anticonvulsive effects and has been applied in the treatment of epilepsy in Oriental medicine. In this study, the effect of alkaloid fraction of U. rhynchophylla against N-methyl-D-aspartate (NMDA)-induced neuronal cell death was investigated. Pretreatment with an alkaloid fraction of U. rhynchophylla for 1 h decreased the degree of neuronal damage induced by NMDA exposure in cultured hippocampal slices and also inhibited NMDA-induced enhanced expressions of apoptosis-related genes such as c-jun, p53, and bax. In the present study, the alkaloid fraction of U. rhynchophylla was shown to have a protective property against NMDA-induced cytotoxicity by suppressing the NMDA-induced apoptosis in rat hippocampal slices.

Implementación de medidas de prevención y control de riesgo ergonómico por levantamiento de pesos y posturas forzadas en la parte operativa de un centro de distribución de alimentos.

OpenAIRE

León Echeverría, Elsi Verónica

2016-01-01

El presente trabajo se realizó con el objetivo de implementar medidas de prevención y control de los riesgos ergonómicos, particularmente por levantamiento de pesos y posturas forzadas en la parte operativa de un centro de distribución de alimentos. Para la evaluación de posturas forzadas se empleó el Método REBA: Evaluación Rápida de Cuerpo Entero (Rapid Entire Body Assessment) y para la evaluación del levantamiento de pesos en tareas simples se empleó la Guía Técnica para La Evaluación y Pr...

Materiales compuestos C/SiC para aplicaciones estructurales de alta temperatura. Parte II: Sistemas de protección contra la oxidación

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Aparicio, M.

2001-02-01

Full Text Available The fact which currently excludes the use of C/SiC composites in high temperature structural applications is the high oxidation rate of carbon fibres at temperatures higher than 450ºC. In this second part of the paper, a review of the different oxidation protection systems, including inhibitors, surface modification of composites, coatings and previous infiltration of the substrates, has been carried out. The addition of inhibitors reduces the oxidation rate, but only up to 850ºC, while the surface modification of composites leads to thin coatings with poor thermal shock resistance. On the other hand, the external layers are the most usual method employed because allows combining different compositions and thicknesses. The multilayer coatings are especially interesting in applications with wide temperature range and thermal shocks requirements. The infiltration of substrate porosity improves slightly the oxidation resistance of C/SiC composites reducing the oxygen accessibility to carbon fibres. However, the infiltration complements very well the oxidation protection performance of a coating system at low temperature, since these normally present open cracks due to mismatch between coating and substrate thermal expansion coefficients.

La utilización de los materiales compuestos C/SiC en aplicaciones estructurales a alta temperatura está limitada por la elevada velocidad de oxidación de la fibra de carbono a temperaturas superiores de 450ºC. En esta segunda parte del trabajo se realiza una revisión de las posibilidades de protección contra la oxidación de estos materiales, incluyendo inhibidores, modificación superficial del material compuesto, recubrimientos e infiltración previa del sustrato. La eficacia de los inhibidores de la reacción de oxidación esta restringida a temperaturas de hasta 850ºC, mientras que la modificación superficial del material compuesto da lugar a capas delgadas y poco resistentes a los ciclos t

Electronic excitation induced structural and optical modifications in InGaN/GaN quantum well structures grown by MOCVD

Energy Technology Data Exchange (ETDEWEB)

Prabakaran, K.; Ramesh, R.; Jayasakthi, M.; Surender, S.; Pradeep, S. [Crystal Growth Centre, Anna University, Chennai (India); Balaji, M. [National Centre for Nanoscience and Nanotechnology, University of Madras, Guindy Campus, Chennai (India); Asokan, K. [Inter-University Accelerator Centre, New Delhi (India); Baskar, K., E-mail: drbaskar2009@gmail.com [Crystal Growth Centre, Anna University, Chennai (India); Manonmaniam Sundaranar University, Tirunelveli (India)

2017-03-01

Highlights: • Effects on InGaN/GaN QW structures by Au{sup 7+} (100 MeV) ion have been investigated. • Structural defects of the irradiated InGaN/GaN QW structures are determined. • The intermixing effect in irradiated InGaN/GaN QW structures were understood. • Modified luminescence was observed in the PL spectra due to heavy ion irradiation. • Surface modification was observed due to the heavy ion irradiation. - Abstract: The present study focuses on the electronic excitation induced structural and optical properties of InGaN/GaN quantum well (QW) structures grown by metal organic chemical vapor deposition technique. These excitations were produced using Au{sup 7+} ion irradiation with 100 MeV energy. The X-ray rocking curves intensity and full width at half-maximum values corresponding to the planes of (0 0 0 2) and (1 0 −1 5) of the irradiated QW structures show the modifications in the screw and edge-type dislocation densities vary with the ion fluences. The structural characteristics using the reciprocal space mapping indicate the intermixing effects in InGaN/GaN QW structures. Atomic force microscopy images confirmed the presence of nanostructures and the surface modification due to heavy ion irradiation. The irradiated QW structures exhibited degraded photoluminescence intensity and a subsequent decrease in the yellow luminescence band intensity with the fluences of 1 × 10{sup 11} and 5 × 10{sup 12} ions/cm{sup 2} compared to the pristine QW structures.

Land-use induced dynamics of C, N and P in mountain soils of South Ecuador

Science.gov (United States)

Hamer, U.; Potthast, K.; Makeschin, F.

2009-04-01

The mountain rainforest region in South Ecuador is characterised by sites subjected to forest clearing by slash burn for pasture production. Repeated burning of pastures is a common management practice in South Ecuador. With ongoing pasture age bracken (Pteridium arachnoideum) outcompetes the pasture grass (Setaria sphacelata), pastures are abandoned and a vegetation succession develops. Along a land-use gradient (natural forest, young and old pasture, abandoned pasture with successional vegetation) the dynamics of C, N and P in the mountain soils were investigated. The study sites were located close to the "Estacion Científica San Francisco", about halfway between the province capitals Loja and Zamora, in the Cordillera Real, an eastern range of the South Ecuadorian Andes at about 2000 m above sea level. The mean annual air temperature is 15.3°C with an average annual rainfall of 2176 mm. The land-use change induced an increase of total P in the top soil (0-30 cm) of young and old pastures. An increase in SOC stocks in the top soil of the old pasture was combined with an increase in the proportion of NaOH extractable organic P. In the young pasture soil the mineralization of SOC and the amounts of microbial biomass C, N and P were highest. In 0-5 cm depth gross N mineralization and gross NH4 consumption rates were significantly higher in the young pasture compared to forest and abandoned pasture. Thus, the initial increase in microbial activity after forest to pasture conversion seems to slow down with increasing pasture age. Burning on the abandoned pasture site induced a short-term and short-lived increase in gross N mineralization rates. First results indicate that the land-use induced changes in mineralization rates were connected with changes in the microbial community structure.

Modelización avanzada de columnas de destilación de operación discontinua

OpenAIRE

Mehlhorn, Arndt

1998-01-01

La tesis doctoral se compone de dos partes fundamentales: El desarrollo teórico de un modelo de simulación para la destilación discontinua y la validación de este mediante experimentos hechos en una planta piloto de destilación discontinua. La parte teórica se divide en la parte de desarrollo del modelo y en la parte de la implementación del modelo en un programa de simulación. El nuevo modelo desarrollado es un modelo de transferencia de materia que se distingue de los desarrollos anteriores...

Experimental study on carcinoma of the stomach in rats induced by administration of N-methyl-N'-nitro-N-nitrosoguanidine and x-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Haizuka, S [Hiroshima Univ. (Japan).School of Medicine

1979-12-01

Induction of gastrointestinal cancer in 109 6-week-old wistar rats (54 males, 55 females) divided into 6 groups was carried out with various combinations of localized x-ray irradiation and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Carcinoma of the glandular part of the stomach and duodenum was found in 50% of the rats in group 1 (localized x-ray irradiation, 2000 R), in 73.3% in group 2 (80 ..mu..g/ml of MNNG in drinking water), in 52.9% in group 3 (x-ray irradiation, 2000 R; MNNG), in 78% in group 4 (x-ray irradiation + oral MNNG at the same time), and in 72.7% in group 5 (oral MNNG + x-ray irradiation). Group 6 was not treated. Most of the cases of carcinoma developed in the antrum of the glandular part of the stomach. Of the histological types of carcinoma, very differentiated tubular adenocarcinoma was the most frequent. Sarcoma of the glandular part of the stomach, which was frequently complicated by carcinoma, was seen in 14.2% of the rats in group 1 and in 45.5% in group 5. Two kinds of adenomatous hyperplasia of the gastroduodenal mucosa were noted in the treated groups. In group 1, only downward adenomatous hyperplasia was seen. In group 2, two kinds of adenomatous hyperplasia were located in the antrum only. In groups 3, 4, and 5, two kinds of adenomatous hyperplasia were found in the antrum and duodenum. Most of the cases of adenomatous hyperplasia were complicated by adenocarcinoma, which frequently results from a downward type of adenomatous hyperplasia. Intestinal metaplasia of the gastric mucosa occurred often in group 4 (71.4%) and group 5 (72.7%). Squamous metaplasia of the gastric mucosa occurred frequently in the limiting ridge. There was no difference between groups 1 and 2 regarding the incidence of squamous metaplasia (25%) while group 4 showed the highest rate (71.4%).

Minithyrotomy with radiofrequency-induced thermotherapy for the treatment of adductor spasmodic dysphonia.

Science.gov (United States)

Desai, Shaun C; Park, Andrea M; Chernock, Rebecca D; Paniello, Randal C

2016-10-01

A simple, safe and effective surgical alternative for treating adductor spasmodic dysphonia (ADSD) would appeal to many patients. This study evaluates a new option, using radiofrequency-induced thermotherapy (RFITT) of the thyroarytenoid muscle (TA) via the minithyrotomy approach to reduce the force of adduction. Fifteen dogs were used. In part 1, the optimal RFITT power settings, exposure time, probe location, and number of passes were determined. Part 2 compared laryngeal adductor pressures (LAPs) at baseline; immediately postintervention; and at 1, 3, or 6 months postintervention. Interventions included RFITT via the transcervical minithyrotomy approach (n = 15), transoral RFITT (n = 3), botulinum toxin (Botox) injection (n = 3), or no-intervention controls (n = 3). Postintervention induced phonation and histologic analyses were performed as well. In the minithyrotomy RFITT group, the mean LAP was 30.3% of baseline immediately posttreatment. At 1, 3, and 6 months postoperatively, the mean LAPs were 24.9%, 44.8%, and 43.5%, respectively. Transoral RFITT reduced LAP to 56.6% of baseline immediately posttreatment, but returned to normal in the 1 and 3 month animals. The Botox injections dropped the LAP to 57% of baseline at 1 month, but returned to normal at 3 months. Mucosal waves, based on induced phonation stroboscopy, were present at the terminal date in all animals. Thirteen of 15 transcervical RFITT preparations (87%) showed no injury to the lamina propria, whereas 80% showed evidence of TA muscle atrophy and fibrosis. Minithyrotomy RFITT is a feasible technique that shows encouraging long-term results for the potential treatment of patients with ADSD. N/A. Laryngoscope, 126:2325-2329, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

[Functional morphology of the vagus nerve nuclei changes in the medulla oblongata (N. Ambiguus, N. Dorsalis), induced by influenza a (H(3)N(I)) in experiment].

Science.gov (United States)

Gogiashvili, L; Abashidze, T; Tsagareli, Z; Dgebuadze, M; Kvachadze, T

2012-12-01

Morphological changes of the brain cortex IV-V layers, the structures of n. ambiguus, n. dorsalis and n. vagus ganglia on the model of influenza virus A strains (H3NI) MLD50 in number 50 microns intranasal inoculation in mice aged 6-8 weeks were studied. For assessment of virus-induced pathology 2 series of experiments were carried out. Electron microscopy, morphometric and histological methods, including by Nissl stain were used. LD dose, daily loss of body weight with access to the so-called "endpoint" determined previously. Experimental period from 48 hours to 12 days. It is shown that in n.vagus stem structures in the medulla oblongata (n. dorsalis, n. ambiguus) have the mosaic and the polymorphic nature of the changes - signs of influenza virus cytotropic effect, such as swelling, vacuolation, chromatolysis, less pyknosis and hyperchromatosis. In the period of the greatest weight loss and expressed «endpoint» irreversible changes in the stem structures associated with n. vagus - apoptotic nuclei and neurons massive edema, lipofuscin accumulation have taken place. Results of the study suggest that the parasympathetic nervous system (n. vagus) may be one of the possible route of influenza A virus (H3NI) genomic structures transnerval invasion in the central nervous system during experimental infection.

UV and IR laser induced ablation of Al2O3/SiN:H and a-Si:H/SiN:H

Directory of Open Access Journals (Sweden)

Schutz-Kuchly T.

2014-01-01

Full Text Available Experimental work on laser induced ablation of thin Al2O3(20 nm/SiN:H (70 nm and a-Si:H (20 nm/SiN:H (70 nm stacks acting, respectively, as p-type and n-type silicon surface passivation layers is reported. Results obtained using two different laser sources are compared. The stacks are efficiently removed using a femtosecond infra-red laser (1030 nm wavelength, 300 fs pulse duration but the underlying silicon surface is highly damaged in a ripple-like pattern. This collateral effect is almost completely avoided using a nanosecond ultra-violet laser (248 nm wavelength, 50 ns pulse duration, however a-Si:H flakes and Al2O3 lace remain after ablation process.

Attenuation of ischemia-reperfusion-induced alterations in intracellular Ca2+ in cardiomyocytes from hearts treated with N-acetylcysteine and N-mercaptopropionylglycine.

Science.gov (United States)

Saini-Chohan, Harjot K; Dhalla, Naranjan S

2009-12-01

This study was undertaken to test whether Ca(2+)-handling abnormalities in cardiomyocytes after ischemia-reperfusion (I/R) are prevented by antioxidants such as N-acetyl L-cysteine (NAC), which is known to reduce oxidative stress by increasing the glutathione redox status, and N-(2-mercaptopropionyl)-glycine (MPG), which scavenges both peroxynitrite and hydroxyl radicals. For this purpose, isolated rat hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion, and cardiomyocytes were prepared to monitor changes in the intracellular concentration of free Ca(2+) ([Ca(2+)](i)). Marked depression in the left ventricular developed pressure and elevation in the left ventricular end-diastolic pressure in I/R hearts were attenuated by treatment with NAC or MPG. Cardiomyocytes obtained from I/R hearts showed an increase in the basal level of [Ca(2+)](i) as well as augmentation of the low Na(+)-induced increase in [Ca(2+)](i), with no change in the KCl-induced increase in [Ca(2+)](i). These I/R-induced alterations in Ca(2+) handling by cardiomyocytes were attenuated by treatment of hearts with NAC or MPG. Furthermore, reduction in the isoproterenol-, ATP-, ouabain-, and caffeine-induced increases in [Ca(2+)](i) in cardiomyocytes from I/R hearts were limited by treatment with NAC or MPG. The increases in the basal [Ca(2+)](i), unlike the KCl-induced increase in [Ca(2+)](i), were fully or partially prevented by both NAC and MPG upon exposing cardiomyocytes to hypoxia-reoxygenation, H(2)O(2), or a mixture of xanthine and xanthine oxidase. These results suggest that improvement in cardiac function of I/R hearts treated with NAC or MPG was associated with attenuation of changes in Ca(2+) handling by cardiomyocytes, and the results support the view that oxidative stress due to oxyradical generation and peroxynitrite formation plays an important role in the development of intracellular Ca(2+) overload in cardiomyocytes as a consequence of I/R injury.

Study of ethanol-induced Golgi disorganization reveals the potential mechanism of alcohol-impaired N-glycosylation

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Casey, Carol A.; Bhat, Ganapati; Holzapfel, Melissa S.; Petrosyan, Armen

2016-01-01

Background It is known that ethanol (EtOH) and its metabolites have a negative effect on protein glycosylation. The fragmentation of the Golgi apparatus induced by alteration of the structure of largest Golgi matrix protein, giantin, is the major consequence of damaging effects of EtOH-metabolism on the Golgi, however, the link between this and abnormal glycosylation remains unknown. Because previously we have shown that Golgi morphology dictates glycosylation, we examined the effect EtOH administration has on function of Golgi residential enzymes involved in N-glycosylation. Methods HepG2 cells transfected with mouse ADH1 (VA-13 cells) were treated with 35 mM ethanol for 72 h. Male Wistar rats were pair-fed Lieber-DeCarli diets for 5 to 8 weeks. Characterization of Golgi-associated mannosyl (α-1,3-)-glycoprotein beta-1,2-N-acetylglucosaminyltransferase (MGAT1), α-1,2-mannosidase (Man-I) and α-mannosidase II (Man-II) were performed in VA-13 cells and rat hepatocytes followed by 3D Structured Illumination Microscopy (SIM). Results First, we detected that EtOH administration results in the loss of sialylated N-glycans on asialoglycoprotein receptor, however the high mannose-type N-glycans are increased. Further analysis by 3D SIM microscopy revealed that EtOH treatment despite Golgi disorganization does not change cis-Golgi localization for Man-I, but does induce medial-to-cis relocation of MGAT1 and Man-II. Using different approaches, including electron microscopy, we revealed that EtOH treatment results in dysfunction of Arf1 GTPase followed by a deficiency in COPI vesicles at the Golgi. Silencing beta-COP or expression of GDP-bound mutant Arf1(T31N) mimics the EtOH effect on retaining MGAT1 and Man-II at the cis-Golgi, suggesting that (a) EtOH specifically blocks activation of Arf1, and (b) EtOH alters the proper localization of Golgi enzymes through impairment of COPI. Importantly, the level of MGAT1 was reduced, because likely MGAT1, contrary to Man-I and Man

The ED95 of Nalbuphine in Outpatient-Induced Abortion Compared to Equivalent Sufentanil.

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Chen, Limei; Zhou, Yamei; Cai, Yaoyao; Bao, Nana; Xu, Xuzhong; Shi, Beibei

2018-04-07

This prospective study evaluated the 95% effective dose (ED 95 ) of nalbuphine in inhibiting body movement during outpatient-induced abortion and its clinical efficacy versus the equivalent of sufentanil. The study was divided into two parts. For the first part, voluntary first-trimester patients who needed induced abortions were recruited to measure the ED 95 of nalbuphine in inhibiting body movement during induced abortion using the sequential method (the Dixon up-and-down method). In the second part, this was a double-blind, randomized study. Sixty cases of first-trimester patients were recruited and were randomly divided into two groups (n = 30), including group N (nalbuphine at the ED 95 dose) and group S (sufentanil at an equivalent dose). Propofol was given to both groups as the sedative. The circulation, respiration and body movement of the two groups in surgery were observed. The amount of propofol, the awakening time, the time to leave the hospital and the analgesic effect were recorded. The ED 95 of nalbuphine in inhibiting body movement during painless surgical abortion was 0.128 mg/kg (95% confidence intervals 0.098-0.483 mg/kg). Both nalbuphine and the equivalent dose of sufentanil provided a good intraoperative and post-operative analgesic effect in outpatient-induced abortion. However, the post-operative morbidity of dizziness for nalbuphine was less than for sufentanil (p abortion as an intraoperative and post-operative analgesic and showed a better effect compared with sufentanil. © 2018 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Antihypertensive effect of rhizome part of Acorus calamus on renal artery occlusion induced hypertension in rats

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Pinal Patel

2012-05-01

Full Text Available Objective: The rhizomes part of Acorus calamus (AC having the calcium inhibitory effect and diuretic activity which may potentiate Na+ excretion in hypertension induced by occlusion of renal artery. Therefore this study was aimed to investigate the effect of AC on experimentally induced hypertension. Methods: Hypertension in rats was induced by clamping the left renal artery for 4h by arterial clamp (2K1C. At the end of experiment animal were anesthetized with ketamine (50 mg/kg. Carotid artery was cannulated which was connected to pressure transducer for estimation of blood pressure. Results: Ethyl acetate extract of Acorus calamus rhizomes (EAAC treated rats that underwent hypertension, demonstrated significant (P < 0.01 lower systolic blood pressure and diastolic blood pressure when compared with 2K1C rats indicated blood pressure lowering activity. Plasma renin activity was significantly (P < 0.05 decreased in EAAC treated rats compared to 2K1C rats. EAAC treated rats that underwent hypertension demonstrated significant (P < 0.01 lower mean blood urea nitrogen and creatinine when compared with 2K1C rats. Lipid peroxidation was significantly (P < 0.001 decreased, where as nitric oxide level in tissue was significantly elevated in EAAC treated rats. Antioxidant enzymes like glutathione, superoxide dismutase and catalase were significantly (P < 0.05, P < 0.01, P < 0.001 increased in EAAC treated rats when compared to 2K1C rats. Conclusions: In conclusions, EAAC treatment attenuated renal artery occlusion induced hypertension via nitric oxide generation and decreases the plasma renin activity.

H5N1 whole-virus vaccine induces neutralizing antibodies in humans which are protective in a mouse passive transfer model.

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M Keith Howard

Full Text Available BACKGROUND: Vero cell culture-derived whole-virus H5N1 vaccines have been extensively tested in clinical trials and consistently demonstrated to be safe and immunogenic; however, clinical efficacy is difficult to evaluate in the absence of wide-spread human disease. A lethal mouse model has been utilized which allows investigation of the protective efficacy of active vaccination or passive transfer of vaccine induced sera following lethal H5N1 challenge. METHODS: We used passive transfer of immune sera to investigate antibody-mediated protection elicited by a Vero cell-derived, non-adjuvanted inactivated whole-virus H5N1 vaccine. Mice were injected intravenously with H5N1 vaccine-induced rodent or human immune sera and subsequently challenged with a lethal dose of wild-type H5N1 virus. RESULTS: Passive transfer of H5N1 vaccine-induced mouse, guinea pig and human immune sera provided dose-dependent protection of recipient mice against lethal challenge with wild-type H5N1 virus. Protective dose fifty values for serum H5N1 neutralizing antibody titers were calculated to be ≤1∶11 for all immune sera, independently of source species. CONCLUSIONS: These data underpin the confidence that the Vero cell culture-derived, whole-virus H5N1 vaccine will be effective in a pandemic situation and support the use of neutralizing serum antibody titers as a correlate of protection for H5N1 vaccines.

Hepatoprotective and Antioxidant activity of Scoparia dulcis Linn, against N Nitrosodiethylamine (DEN) induced Hepatotoxicity in experimental Rats

OpenAIRE

Langeswaran K; Jagadeesan A. J; Vijayaprakash S; Balasubramanian M. P

2012-01-01

Scoparia dulcis Linn, belongs to the family Scrophulariaceae and have speculated Medicinal properties. In this present investigation, the antioxidant and hepatoprotective activity of the aqueous extracts of Scoparia dulcis was evaluated against N-nitrosodiethylamine (DEN) induced liver cirrhosis in experimental rats. In group III hepatotoxicity induced animals, an oral dose of 500 mg/kg, of the aqueous extracts of Scoparia dulcis exhibited a significant (P

Temperature dependence on plasma-induced damage and chemical reactions in GaN etching processes using chlorine plasma

Science.gov (United States)

Liu, Zecheng; Ishikawa, Kenji; Imamura, Masato; Tsutsumi, Takayoshi; Kondo, Hiroki; Oda, Osamu; Sekine, Makoto; Hori, Masaru

2018-06-01

Plasma-induced damage (PID) on GaN was optimally reduced by high-temperature chlorine plasma etching. Energetic ion bombardments primarily induced PID involving stoichiometry, surface roughness, and photoluminescence (PL) degradation. Chemical reactions under ultraviolet (UV) irradiation and chlorine radical exposure at temperatures higher than 400 °C can be controlled by taking into account the synergism of simultaneous photon and radical irradiations to effectively reduce PID.

p-n Junction Dynamics Induced in a Graphene Channel by Ferroelectric-Domain Motion in the Substrate

International Nuclear Information System (INIS)

Kurchak, Anatolii I.; Eliseev, Eugene A.; Kalinin, Sergei V.; Strikha, Maksym V.; Morozovska, Anna N.

2017-01-01

The p - n junction dynamics induced in a graphene channel by stripe-domain nucleation, motion, and reversal in a ferroelectric substrate is explored using a self-consistent approach based on Landau-Ginzburg-Devonshire phenomenology combined with classical electrostatics. Relatively low gate voltages are required to induce the hysteresis of ferroelectric polarization and graphene charge in response to the periodic gate voltage. Pronounced nonlinear hysteresis of graphene conductance with a wide memory window corresponds to high amplitudes of gate voltage. Also, we reveal the extrinsic size effect in the dependence of the graphene-channel conductivity on its length. We predict that the top-gate–dielectric-layer–graphene-channel–ferroelectric-substrate nanostructure considered here can be a promising candidate for the fabrication of the next generation of modulators and rectifiers based on the graphene p - n junctions.

Potencialização do efeito metemoglobinizante da dapsona em ratos pela N-acetilcisteína Potentiation of dapsone induced methemoglobinemia by N-acetylcysteine in rats

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Natália Valadares de Moraes

2008-03-01

Full Text Available Dapsona (DDS (4,4'diaminodifenilsulfona, fármaco de escolha para o tratamento da hanseníase, freqüentemente induz anemia hemolítica e metemoglobinemia. A N-hidroxilação, uma de suas principais vias de biotransformação, é constantemente relacionada com a metemoglobinemia observada com o uso do fármaco. Com o objetivo de prevenir a hemotoxicidade induzida pela DDS, N-acetilcisteína, fármaco precursor de glutationa, foi administrada em associação com DDS em ratos machos Wistar pesando 220-240 g. Os animais foram anestesiados e o sangue coletado da aorta para determinação da concentração plasmática de DDS por CLAE, determinação dos níveis de metemoglobina e de glutationa eritrocitária por espectrofotometria, e avaliação de parâmetros bioquímicos e hematológicos. Os resultados obtidos mostraram que a N-acetilcisteína potenciou o efeito metemoglobinizante da dapsona devido ao aumento de sua concentração plasmática e conseqüente aumento da formação da N-hidroxilamina. Concluímos que as interações medicamentosas com a dapsona exigem estudos individualizados a fim de evitar os efeitos adversos do fármaco.Dapsone (DDS (4,4'diaminodiphenylsulfone, the drug of choice for the treatment of leprosy, frequently induces hemolytic anemia and methemoglobinemia. N-hydroxylation, one of the major pathways of biotransformation, has been constantly related to the methemoglobinemia after the use of the drug. In order to prevent the dapsone-induced hemotoxicity, N-acetylcysteine, a drug precursor of glutathione, was administered in combination with DDS to male Wistar rats, weighting 220-240 g. The animals were then anaesthetized and blood was collected from the aorta for determination of plasma DDS concentration by HPLC, determination of methemoglobinemia and glutathione by spectrophotometry, and for biochemical and hematological parameters. Our results showed that N-acetylcysteine enhanced dapsone-induced methemoglobinemia due to

Extracción de cromo con disolventes orgánicos. III parte. Aplicación al tratamiento de residuos polimetálicos industriales

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de Juan, D.

1998-10-01

Full Text Available The use of Primene 81R as extraction agent of chromium present in solid wastes containing nickel, iron and copper has been studied. The waste was leached with a sulphuric acid solution up to pH 3 and oxidation of Cr(III to Cr(VI with Caro acid was also studied. Because of the negative result of oxidation, the treatment was applied on Cr(III directly. Extraction/scrubbing/stripping process was studied in the leach. The composition of organic phase used in the extraction step was 10 % v/v Primene 81R, 10 % isodecanol and kerosene. All the iron, 91 % Cr, 10 % Ni and large part of the copper contained in the initial leach solution are recovered in the organic phase. In the scrubbing stage (with a sulphuric acid solution at pH 1,4, all the copper and nickel and 30 % Cr go to the washing liquor, while all the iron and 70 % Cr remained in the organic phase. In the stripping stage (with a 2N NH₄OH or 2N NaOH solution all the iron and chromium are recovered as a precipitate of highly absorbent hydroxides. After the treatment mentioned, 63 % Cr and 100 % Fe are recovered as a mixture of hydroxides, and 28 % of the initial chromium, all the nickel and the copper are found in the washing liquor.

Se estudia la aplicación del Primene 81R como agente de extracción del cromo presente en residuos sólidos que poseen níquel, hierro y cobre. El residuo se lixivió con disolución de ácido sulfúrico hasta pH 3 y se investigó la oxidación del Cr(III a Cr(VI con ácido de Caro. Ante el nulo resultado en la oxidación, se actuó directamente sobre el Cr(III. Se estudió el proceso de extracción/lavado/reextracción sobre la lejía de lixiviación. La fase orgánica empleada en la extracción estaba constituida por 10 % v/v de Primene 81R, 10 % de isodecanol y queroseno. En la fase orgánica se recupera todo el hierro, el 91 % Cr, el 10 % Ni y gran parte del cobre contenidos en la lejía de partida. En la etapa de lavado (con disolución de �

Internacionalización de la industria española de fondos de inversión y cambios de categorías

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Laura Andreu-Sánchez

2010-08-01

Full Text Available Este artículo muestra la evolución de los fondos de inversión desde la perspectiva de la composición de sus carteras. En el periodo 1999-2006 se observa un importante incremento de la diversificación internacional, tanto en partícipes, por el crecimiento experimentado por los fondos internacionales, como en gestores, ya que incorporan cada vez mayores porcentajes de activos internacionales en sus carteras. El dinamismo de la industria de fondos de inversión induce frecuentes cambios de categorías. Teóricamente, estos cambios se producen tras la modificación de la política de inversión. No obstante, se demuestra empíricamente que los fondos de inversión pueden abandonar una categoría por motivos más relacionados con el marketing.

Nuevas perspectivas en la evaluación de las patentes como parte del curriculum científico

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Guasch, Luis M.

2007-06-01

Full Text Available During the last years the consideration of the patents as part of the scientific curriculum has been changing from the activity of technologists and researchers devoted to applied science to a fundamental part of the scientific curriculum of well-known researchers. Some time ago, patents were simply not considered in teaching evaluation at University or its equivalent at CSIC (Spanish National Research Council and only considered as a second range parameter in the scientific evaluation. In promotion competition they have change from a marginal factor when the number of papers and their impact factor were comparable, to become a decisive factor or even a «sine qua non» condition in specific areas. As it happens to a great extent in publications, the number of patent applications is not an indicator of the quality or importance of the knowledge they present; however their monopoly of exploitation and its costs makes patents totally different and introduces variables difficult to quantify in scientific evaluation. Changes in CSIC legal structure and management definition as a Key Institution in the Spanish Innovation System and the fact of its being the most active patent applicant (5th public institution as EPO applicant, besides the changes in its Technology Transfer management, should affect the decision to patent. Its value in research activity acknowledgement requires more precise indicators to reflect «ex ante» its impact on the scientific community as well as on society welfare, because at the end of patent life its real market incidence shows the impact of the research results presented in a patent.

En los últimos años la consideración de las patentes como currículo del investigador ha ido cambiando progresivamente, de ser la actividad propia de tecnólogos e investigadores centrados en investigación aplicada, a ser también parte fundamental del currículo de investigadores de prestigio en ciencia básica. Antes

Tentativa de evaluación de los efectos, beneficiosos o perjudiciales, de los aluminatos del cemento sobre las cualidades del hormigón. Primera parte

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Schramll, W.

1979-03-01

Full Text Available El autor expone, en esta primera parte, la cuestión desde el punto de vista del fabricante limitándose a las consecuencias apreciables en las cualidades del hormigón. Trata de responder a dos preguntas: ¿Por qué se debe cambiar el contenido de aluminato tricálcico de un cemento? ¿Qué beneficios, o que perjuicios, producen con el cambio? El objetivo final será poder establecer un análisis "costo-beneficio" correspondiente a cada cambio.

Effects of the strain relaxation of an AlGaN barrier layer induced by various cap layers on the transport properties in AlGaN/GaN heterostructures

International Nuclear Information System (INIS)

Liu Zi-Yang; Zhang Jin-Cheng; Duan Huan-Tao; Xue Jun-Shuai; Lin Zhi-Yu; Ma Jun-Cai; Xue Xiao-Yong; Hao Yue

2011-01-01

The strain relaxation of an AlGaN barrier layer may be influenced by a thin cap layer above, and affects the transport properties of AlGaN/GaN heterostructures. Compared with the slight strain relaxation found in AlGaN barrier layer without cap layer, it is found that a thin cap layer can induce considerable changes of strain state in the AlGaN barrier layer. The degree of relaxation of the AlGaN layer significantly influences the transport properties of the two-dimensional electron gas (2DEG) in AlGaN/GaN heterostructures. It is observed that electron mobility decreases with the increasing degree of relaxation of the AlGaN barrier, which is believed to be the main cause of the deterioration of crystalline quality and morphology on the AlGaN/GaN interface. On the other hand, both GaN and AlN cap layers lead to a decrease in 2DEG density. The reduction of 2DEG caused by the GaN cap layer may be attributed to the additional negative polarization charges formed at the interface between GaN and AlGaN, while the reduction of the piezoelectric effect in the AlGaN layer results in the decrease of 2DEG density in the case of AlN cap layer. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

On-chip photonic system using suspended p-n junction InGaN/GaN multiple quantum wells device and multiple waveguides

International Nuclear Information System (INIS)

Wang, Yongjin; Zhu, Guixia; Gao, Xumin; Yang, Yongchao; Yuan, Jialei; Shi, Zheng; Zhu, Hongbo; Cai, Wei

2016-01-01

We propose, fabricate, and characterize the on-chip integration of suspended p-n junction InGaN/GaN multiple quantum wells (MQWs) device and multiple waveguides on the same GaN-on-silicon platform. The integrated devices are fabricated via a wafer-level process and exhibit selectable functionalities for diverse applications. As the suspended p-n junction InGaN/GaN MQWs device operates under a light emitting diode (LED) mode, part of the light emission is confined and guided by the suspended waveguides. The in-plane propagation along the suspended waveguides is measured by a micro-transmittance setup. The on-chip data transmission is demonstrated for the proof-of-concept photonic integration. As the suspended p-n junction InGaN/GaN MQWs device operates under photodiode mode, the light is illuminated on the suspended waveguides with the aid of the micro-transmittance setup and, thus, coupled into the suspended waveguides. The guided light is finally sensed by the photodiode, and the induced photocurrent trace shows a distinct on/off switching performance. These experimental results indicate that the on-chip photonic integration is promising for the development of sophisticated integrated photonic circuits in the visible wavelength region.

Wafer-scale laser pantography: Fabrication of n-metal-oxide-semiconductor transistors and small-scale integrated circuits by direct-write laser-induced pyrolytic reactions

International Nuclear Information System (INIS)

McWilliams, B.M.; Herman, I.P.; Mitlitsky, F.; Hyde, R.A.; Wood, L.L.

1983-01-01

A complete set of processes sufficient for manufacture of n-metal-oxide-semiconductor (n-MOS) transistors by a laser-induced direct-write process has been demonstrated separately, and integrated to yield functional transistors. Gates and interconnects were fabricated of various combinations of n-doped and intrinsic polysilicon, tungsten, and tungsten silicide compounds. Both 0.1-μm and 1-μm-thick gate oxides were micromachined with and without etchant gas, and the exposed p-Si [100] substrate was cleaned and, at times, etched. Diffusion regions were doped by laser-induced pyrolytic decomposition of phosphine followed by laser annealing. Along with the successful manufacture of working n-MOS transistors and a set of elementary digital logic gates, this letter reports the successful use of several laser-induced surface reactions that have not been reported previously

Dispersion induced penalty for a 1xN passive interferometric optical MUX/DEMUX and its reduction using all-pass filters

DEFF Research Database (Denmark)

Leick, Lasse; Peucheret, Christophe

2002-01-01

The cascadability of 1timesN passband flattened interferometer DEMUX is investigated numerically. The passband flattening process results in detrimental dispersion induced penalty at 10 Gbit/s which can be significantly reduced with all-pass filters on the input arm......The cascadability of 1timesN passband flattened interferometer DEMUX is investigated numerically. The passband flattening process results in detrimental dispersion induced penalty at 10 Gbit/s which can be significantly reduced with all-pass filters on the input arm...

Sequencing analysis of mutations induced by N-ethyl-N-nitrosourea at different sampling times in mouse bone marrow.

Science.gov (United States)

Wang, Jianyong; Chen, Tao

2010-03-01

In our previous study (Wang et al., 2004, Toxicol. Sci. 82: 124-128), we observed that the cII gene mutant frequency (MF) in the bone marrow of Big Blue mice showed significant increase as early as day 1, reached the maximum at day 3 and then decreased to a plateau by day 15 after a single dose of carcinogen N-ethyl-N-nitrosourea (ENU) treatment, which is different from the longer mutation manifestation time and the constancy of MFs after reaching their maximum in some other tissues. To determine the mechanism underlying the quick increase in MF and the peak formation in the mutant manifestation, we examined the mutation frequencies and spectra of the ENU-induced mutants collected from different sampling times in this study. The cII mutants from days 1, 3 and 120 after ENU treatment were randomly selected from different animals. The mutation frequencies were 33, 217, 305 and 144 x 10(-6) for control, days 1, 3, and 120, respectively. The mutation spectra at days 1 and 3 were significantly different from that at day 120. Considering that stem cells are responsible for the ultimate MF plateau (day 120) and transit cells are accountable for the earlier MF induction (days 1 or 3) in mouse bone marrow, we conclude that transit cells are much more sensitive to mutation induction than stem cells in mouse bone marrow, which resulted in the specific mutation manifestation induced by ENU.

Percepción de la participación comunicativa en la conversación peninsular por parte de hablantes de español (L1 y L2) residentes en Suecia

OpenAIRE

Elf, Tora

2007-01-01

El objetivo de este estudio es investigar cuáles son las actitudes que se tienen ante un estilo comunicativo que no es el propio. Suponemos que en el encuentro intercultural estas actitudes pueden provocar malos entendidos. Para eso observamos las reacciones que un grupo de informantes, hablantes de español (L1 y L2), residentes en Suecia, tienen ante conversaciones filmadas en España. La condición para la elección de los informantes, ha sido que éstos no formaran parte de la comunidad de len...

Hyperthermia induced after recirculation triggers chronic neurodegeneration in the penumbra zone of focal ischemia in the rat brain

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L.A. Favero-Filho

2008-11-01

Full Text Available Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT initiated a few hours after transient global ischemia. Since transient global ischemia and ischemic penumbra share pathophysiological similarities, this study addressed the effects of HT induced after recirculation of focal brain ischemia on infarct size during long survival times. Adult male Wistar rats underwent intra-luminal occlusion of the left middle cerebral artery for 60 min followed by HT (39.0-39.5°C or normothermia. Control procedures included none and sham surgery with and without HT, and middle cerebral artery occlusion alone. Part I: 6-h HT induced at recirculation. Part II: 2-h HT induced at 2-, 6-, or 24-h recirculation. Part III: 2-h HT initiated at recirculation or 6-h HT initiated at 2-, 6- or 24-h recirculation. Survival periods were 7 days, 2 or 6 months. The effects of post-ischemic HT on cortex and striatum were evaluated histopathologically by measuring the area of remaining tissue in the infarcted hemisphere at -0.30 mm from bregma. Six-hour HT initiated from 6-h recirculation caused a significant decrease in the remaining cortical tissue between 7-day (N = 8 and 2-month (N = 8 survivals (98.46 ± 1.14 to 73.62 ± 8.99%, respectively. When induced from 24-h recirculation, 6-h HT caused a significant reduction of the remaining cortical tissue between 2- (N = 8 and 6-month (N = 9 survivals (94.97 ± 5.02 vs 63.26 ± 11.97%, respectively. These data indicate that post-ischemic HT triggers chronic neurodegenerative processes in ischemic penumbra, suggesting that similar fever-triggered effects may annul the benefit of early recirculation in stroke patients over the long-term.

A novel H6N1 virus-like particle vaccine induces long-lasting cross-clade antibody immunity against human and avian H6N1 viruses.

Science.gov (United States)

Yang, Ji-Rong; Chen, Chih-Yuan; Kuo, Chuan-Yi; Cheng, Chieh-Yu; Lee, Min-Shiuh; Cheng, Ming-Chu; Yang, Yu-Chih; Wu, Chia-Ying; Wu, Ho-Sheng; Liu, Ming-Tsan; Hsiao, Pei-Wen

2016-02-01

Avian influenza A(H6N1) virus is one of the most common viruses isolated from migrating birds and domestic poultry in many countries. The first and only known case of human infection by H6N1 virus in the world was reported in Taiwan in 2013. This led to concern that H6N1 virus may cause a threat to public health. In this study, we engineered a recombinant H6N1 virus-like particle (VLP) and investigated its vaccine effectiveness compared to the traditional egg-based whole inactivated virus (WIV) vaccine. The H6N1-VLPs exhibited similar morphology and functional characteristics to influenza viruses. Prime-boost intramuscular immunization in mice with unadjuvanted H6N1-VLPs were highly immunogenic and induced long-lasting antibody immunity. The functional activity of the VLP-elicited IgG antibodies was proved by in vitro seroprotective hemagglutination inhibition and microneutralization titers against the homologous human H6N1 virus, as well as in vivo viral challenge analyses which showed H6N1-VLP immunization significantly reduced viral load in the lung, and protected against human H6N1 virus infection. Of particular note, the H6N1-VLPs but not the H6N1-WIVs were able to confer cross-reactive humoral immunity; antibodies induced by H6N1-VLP vaccine robustly inhibited the hemagglutination activities and in vitro replication of distantly-related heterologous avian H6N1 viruses. Furthermore, the H6N1-VLPs were found to elicit significantly greater anti-HA2 antibody responses in immunized mice than H6N1-WIVs. Collectively, we demonstrated for the first time a novel H6N1-VLP vaccine that effectively provides broadly protective immunity against both human and avian H6N1 viruses. These results, which uncover the underlying mechanisms for induction of wide-range immunity against influenza viruses, may be useful for future influenza vaccine development. Copyright © 2015 Elsevier B.V. All rights reserved.

A CVD diamond detector for (n,α) cross-section measurements

International Nuclear Information System (INIS)

Weiss, C.

2014-01-01

A novel detector based on the chemical vapor deposition (CVD) diamond technology has been developed in the framework of this PhD, for the experimental determination of (n,α) cross-sections at the neutron time-of-flight facility n⎽TOF at CERN. The 59 Ni(n,α) 56 Fe cross-section, which is relevant for astrophysical questions as well as for risk-assessment studies in nuclear technology, has been measured in order to validate the applicability of the detector for such experiments. The thesis is divided in four parts. In the introductory part the motivation for measuring (n,α) cross-sections, the experimental challenges for such measurements and the reasons for choosing the CVD diamond technology for the detector are given. This is followed by the presentation of the n⎽TOF facility, an introduction to neutron-induced nuclear reactions and a brief summary of the interaction of particles with matter. The CVD diamond technology and the relevant matters related to electronics are given as well in this first part of the thesis. The second part is dedicated to the design and production of the Diamond Mosaic-Detector (DM-D) and its characterization. The 59 Ni(n,α) 56 Fe cross-section measurement at n⎽TOF and the data analysis are discussed in detail in the third part of the thesis, before the summary of the thesis and an outlook to possible future developments and applications conclude the thesis in the forth part. In this work, the Diamond Mosaic-Detector, which consist of eight single-crystal (sCVD) diamond sensors and one 'Diamond on Iridium' (DOI) sensor has proven to be well suited for (n,α) cross-section measurements for 1 MeV < E α < 22 MeV. The upper limit is given by the thickness of the sensors, d = 150 μm, while the lower limit is dictated by background induced by neutron capture reactions in in-beam materials. The cross-section measurement was focussed on the resonance integral of 59 Ni(n,α) 56 Fe at E n = 203 eV, with the aim of clarifying

Optimización del sistema de control de las pequeñas centrales hidroeléctricas (segunda parte: Modelo matemático de optimización

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Luis Jerónimo García Faure

2011-02-01

Full Text Available En la primera parte de este trabajo se pudo apreciar lo complejo que resulta el proceso de control de laspequeñas centrales hidroeléctricas (PCH mediante la regulación del gasto de agua por la cantidad devariables que en él intervienen. Esto trae como consecuencia que un mismo problema pueda tenermúltiples soluciones, por lo que los métodos de solución que normalmente se utilizan para determinar losparámetros de trabajo del regulador consideran constantes muchas de las variables, obteniéndose unasolución no optimizada del problema.  In the first part of this work it could appreciate the complex thing that is the control process of smallhydropower's (SHP by means of the regulation of the flow of water due to the great quantity of variablesthat intervene in it. This results in the fact that a given problem can have multiple solutions, because thesolution methods that are usually used to determine the parameters of work of the regulator cannot beapplied since they consider constant many of the variables. Therefore, the obtained solution in this waycannot optimize the problem.

U.v.-induced and N-methyl-N'-nitrosoguanidine-induced mutagenesis in Bacillus thuringiensis

International Nuclear Information System (INIS)

Auffray, Y.; Boutibonnes, P.

1987-01-01

The lethal and mutagenic effects of u.v. light and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on Bacillus thuringiensis were investigated. Lethality studies demonstrated that B. thuringiensis was relatively sensitive to these agents. This bacterium was mutated at the rifampicin resistance marker by u.v. light and to a lesser extent by the direct acting alkylating agent MNNG. One mutant selected for its greater sensitivity to u.v. light expressed a higher frequency of mutagenesis after u.v. light treatment and appeared to be defective in an excision repair pathway. However, this mutant was only slightly mutable by MNNG in comparison with the wild-type strain. This unusual phenotype does not yet have a parallel among the radiation sensitive mutants described in other bacterial species. (author)

La separación del almidón de yuca: Evaluación de la sedimentación por gravedad en canales

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Patricia Torres Lozada

2014-01-01

Full Text Available La producción de almidón de yuca en Colombia proviene principalmente del norte del departamento del Cauca, en pequeñas industrias agrícolas llamadas "rallanderías", en las cuales la sedimentación de las partículas suspendidas ocurre en canales. Puesto que el proceso de sedimentación determina la capacidad de la industria del almidón, razón por la cual, se consideró importante evaluar el proceso de sedimentación en los canales rectangulares (0.3x0.4 x 165 m, utilizados generalmente en la región. Se evaluaron dos componentes principales en la zona de decantación: el cambio en la concentración de la suspensión afluente y la distribución del tamaño de la partícula. Con relación al afluente de los canales, se encontró que la concentración de la suspensión durante el funcionamiento del filtro, la mayor parte del tiempo fue entre 0.1 a 6%, predominando la sedimentación de partículas discretas para las cuales aplica la ley de Stokes. En la sedimentación, el flujo varió entre 0.82 a 1.44 L/s con predominio de flujo laminar yTRH> 150 minutos. En los primeros 104 m del canal, las partículas con tamaños> 10 µm fueron retenidas eficientemente; las partículas con tamaños entre 6.7 a 8.8 μm no fueron retenidas, siendo vertidas a los cuerpos de agua y generando así, problemas ambientales.

Prolonged ketamine exposure induces increased activity of the GluN2B-containing N-methyl-d-aspartate receptor in the anterior cingulate cortex of neonatal rats.

Science.gov (United States)

Kokane, Saurabh S; Gong, Kerui; Jin, Jianhui; Lin, Qing

2017-09-01

Ketamine is a commonly used anesthetic among pediatric patients due to its high efficacy. However, it has been demonstrated by several preclinical studies that, widespread accelerated programmed death of neurons (neuroapoptosis) occurs due to prolonged or repeated exposure to ketamine specifically in the neonatal brain. Therefore, an emphasis on understanding the molecular mechanisms underlying this selective vulnerability of the neonatal brain to ketamine-induced neuroapoptosis becomes important in order to identify potential therapeutic targets, which would help prevent or at least ameliorate this neuroapoptosis. In this study, we demonstrated that repeated ketamine administration (6 injections of 20mg/kg dose given over 12h time period) in neonatal (postnatal day 7; PND 7) Sprague-Dawley rats induced a progressive increase in N-methyl-d-aspartate receptor (NMDAR)-mediated excitatory postsynaptic currents (EPSCs) in the neurons of the anterior cingulate cortex (ACC) for up to 6h after the last ketamine dose. Specifically, we observed that the increased EPSCs were largely mediated by GluN2B-containing NMDARs in the neurons of the ACC. Along with increased synaptic transmission, there was also a significant increase in the expression of the GluN2B-containing NMDARs as well. Taken together, these results showed that after repeated exposure to ketamine, the synaptic transmission mediated by GluN2B-containing NMDARs was significantly increased in the neonatal brain. This was significant as it showed for the first time that ketamine had subunit-specific effects on GluN2B-containing NMDARs, potentially implicating the involvement of these subunits in the increased vulnerability of immature neurons of the neonatal brain to ketamine-induced neuroapoptosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Polycrystalline GaN layer recrystallization by metal-induced method during the baking process

Energy Technology Data Exchange (ETDEWEB)

Jagoda, A.; Stanczyk, B.; Dobrzanski, L.; Diduszko, R. [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw 118 (Poland)

2007-04-15

Radio frequency reactive sputtering was used to produce gallium nitride films on thermally oxidized silicon substrates at room temperature. Metallic Ga (purity 6N) was used as the target, N{sub 2} and Ar were utilized as sputtering gases. Amorphous GaN was obtained by metal-induced crystallization with a Ni assistance. The nickel particles were scattered onto the surface by rf sputtering and their density was 2 x 10{sup 14} atoms/cm{sup 2} or 4 x 10{sup 14} atoms/cm{sup 2}, which corresponds to 0.02 nm and 0.04 nm thick layer. These values are less than a monolayer thickness, so they are not continuous. Samples were annealed at 700 C for 3 h and at 900 C for 5 min in a RTP furnace. The 2.5 {mu}m GaN layers grown on the Ni-coated SiO{sub 2} surface recrystallized during annealing forming crystals of (002) orientation. The catalytic regrowth mechanism of GaN is discussed on the basis of experimental results. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Las segundas partes sí pueden ser mejores: algunas reflexiones sobre el uso de datos secundarios en la investigación cualitativa The second parts may be better: some reflections on the use of secondary data in qualitative research

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Adrián Scribano

2009-12-01

Full Text Available El análisis de datos secundarios es una de las estrategias más "antiguas" que los sociólogos han empleado para dar cuenta de fenómenos de la realidad social sobre los que se disponía de información elaborada por otros El presente trabajo tiene por objetivo establecer una reflexión sistemática sobre el uso de información secundaria en los procesos de investigación social cualitativos. El articulo consta de cuatro partes: 1.- hacia una definición de dato y análisis secundario; 2. ventajas y desventajas del uso de información secundaria; 3.- cómo, por qué y para qué re-usar información cualitativa, y 4.- algunas propuestas a modo de apertura de un campo de discusión. Abogamos por establecer criterios claros que puedan facilitar el uso y análisis de información elaborada por otros y/o en diferentes contextos de producción.The analysis of secondary data is one of the "oldest" strategies that sociologists have used to work with the phenomena of social reality when the available information was prepared by others. This study intends to establish a systematic reflection on the use of secondary information in the processes of qualitative social research. The article is divided into four parts: the first works on a definition of data and secondary analysis; the second part discusses advantages and disadvantages of the use of qualitative information; the third asks how, why and what for is the reuse of qualitative information; and finally the fourth part presents some proposals for discussion. The aim is to establish clear criteria that would facilitate the use and analysis of information produced by others and/or in different contexts of production.

O-GlcNAc-specific antibody CTD110.6 cross-reacts with N-GlcNAc2-modified proteins induced under glucose deprivation.

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Takahiro Isono

Full Text Available Modification of serine and threonine residues in proteins by O-linked β-N-acetylglucosamine (O-GlcNAc glycosylation is a feature of many cellular responses to the nutritional state and to stress. O-GlcNAc modification is reversibly regulated by O-linked β-N-acetylglucosamine transferase (OGT and β-D-N-acetylglucosaminase (O-GlcNAcase. O-GlcNAc modification of proteins is dependent on the concentration of uridine 5'-diphospho-N-acetylglucosamine (UDP-GlcNAc, which is a substrate of OGT and is synthesized via the hexosamine biosynthetic pathway. Immunoblot analysis using the O-GlcNAc-specific antibody CTD110.6 has indicated that glucose deprivation increases protein O-GlcNAcylation in some cancer cells. The mechanism of this paradoxical phenomenon has remained unclear. Here we show that the increased glycosylation induced by glucose deprivation and detected by CTD110.6 antibodies is actually modification by N-GlcNAc(2, rather than by O-GlcNAc. We found that this induced glycosylation was not regulated by OGT and O-GlcNAcase, unlike typical O-GlcNAcylation, and it was inhibited by treatment with tunicamycin, an N-glycosylation inhibitor. Proteomics analysis showed that proteins modified by this induced glycosylation were N-GlcNAc(2-modified glycoproteins. Furthermore, CTD110.6 antibodies reacted with N-GlcNAc(2-modified glycoproteins produced by a yeast strain with a ts-mutant of ALG1 that could not add a mannose residue to dolichol-PP-GlcNAc(2. Our results demonstrated that N-GlcNAc(2-modified glycoproteins were induced under glucose deprivation and that they cross-reacted with the O-GlcNAc-specific antibody CTD110.6. We therefore propose that the glycosylation status of proteins previously classified as O-GlcNAc-modified proteins according to their reactivity with CTD110.6 antibodies must be re-examined. We also suggest that the repression of mature N-linked glycoproteins due to increased levels of N-GlcNAc(2-modified proteins is a newly

La ocupación del Pacífico Sur costarricense por parte de la Compañía Bananera (1938-1984.

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Antoni Royo

2011-08-01

Full Text Available El artículo pretende esbozar la historia de la ocupación humana y económica de la región del Pacífico sur costarricense desde la llegada de los primeros pobladores sobre los que existen fuentes, hasta la implantación y posterior desarrollo de actividades de explotación bananera por parte de la Compañía Bananera de Costa Rica, filial de la United Fruit Company. La Compañía Bananera vendrá a insertarse a una dinámica poblacional y económica preexistente que condicionará sus estrategias de implantación. Por su parte, la voluntad estatal de arraigar la Compañía al país mediante los Contratos Bananeros se inscribe en el diseño institucional de poblar y desenclavar económicamente la Zona Sur costarricense. Por último se analiza la estructura operativa de la Compañía y se abordan brevemente las razones que motivaron el cese de operaciones así como sus repercusiones actuales.

Chemopreventive effects of embelin and curcumin against N-nitrosodiethylamine/phenobarbital-induced hepatocarcinogenesis in Wistar rats.

Science.gov (United States)

Sreepriya, M; Bali, Geetha

2005-09-01

The effects of embelin (50 mg/kg/day), a benzoquinone derivative of Embelia ribes, and the effects of curcumin (100 mg/kg/day), the active principle of Curcuma longa, against N-nitrosodiethylamine (DENA)-initiated and phenobarbital (PB)-promoted hepatocarcinogenesis were studied in Wistar rats. They were able to prevent the induction of hepatic hyper plastic nodules, body weight loss, increase in the levels of hepatic diagnostic markers, and hypoproteinemia induced by DENA/PB treatment. Hence, results of our study suggest the possible chemopreventive effects of embelin (EMB) and curcumin (CUR) against DENA/PB-induced hepatocarcinogenesis in Wistar rats.

Quinta parte. Pudriciones Fungosas Radiculares del Fríjol en Valle de Medellín Colombia

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Cárdona Álvarez Canúto

1954-11-01

Full Text Available En esta parte se hace el resumen del estudio que se realizo sobre las pudriciones fungosas radiculares del fríjol en el valle de Medellín, a continuación se enumeran las conclusiones a las que se llegaron: 1A partir de 1948 se hizo un estudio de determinación de los hongos que causan pudriciones de la raíz del fríjol. Dicho estudio se efectuó en Medellín e incluyó organismos de la región y de otros lugares, como Andes, Armero y Palmira. Se usaron organismos que se encontraron asociados con pudriciones de la raíz del fríjol, vigna, remolacha y soya. 2Lo organismos aislados se obtuvieron directamente de las raíces afectadas y no de otra fuente como el suelo o la semilla. 3Concomitante con la obtención de los cultivos de los organismos, se hizo un estudio abarcando apreciación de distribución de los hongos en los plantíos y pérdidas en rendimiento, causadas por los agentes, expresadas en peso de semilla. Se obtuvieron porcentajes naturales de infección variando entre 68.55 y 100% y reducción en el rendimiento hasta del 93%. 4Se hizo una descripción de síntomas y de signos para cada especie patógena encontrada durante este trabajo. Asimismo se estudió la clasificación taxonómica de cada organismo en particular.

Mucosal immunity induced by adenovirus-based H5N1 HPAI vaccine confers protection against a lethal H5N2 avian influenza virus challenge

International Nuclear Information System (INIS)

Park, Ki Seok; Lee, Jiyeung; Ahn, So Shin; Byun, Young-Ho; Seong, Baik Lin; Baek, Yun Hee; Song, Min-Suk; Choi, Young Ki; Na, Yun Jeong; Hwang, Inhwan; Sung, Young Chul; Lee, Chang Geun

2009-01-01

Development of effective vaccines against highly pathogenic avian influenza (HPAI) H5N1 viruses is a global public health priority. Considering the difficulty in predicting HPAI H5N1 pandemic strains, one strategy used in their design includes the development of formulations with the capacity of eliciting broad cross-protective immunity against multiple viral antigens. To this end we constructed a replication-defective recombinant adenovirus-based avian influenza virus vaccine (rAdv-AI) expressing the codon-optimized M2eX-HA-hCD40L and the M1-M2 fusion genes from HPAI H5N1 human isolate. Although there were no significant differences in the systemic immune responses observed between the intramuscular prime-intramuscular boost regimen (IM/IM) and the intranasal prime-intramuscular boost regimen (IN/IM), IN/IM induced more potent CD8 + T cell and antibody responses at mucosal sites than the IM/IM vaccination, resulting in more effective protection against lethal H5N2 avian influenza (AI) virus challenge. These findings suggest that the strategies used to induce multi-antigen-targeted mucosal immunity, such as IN/IM delivery of rAdv-AI, may be a promising approach for developing broad protective vaccines that may be more effective against the new HPAI pandemic strains.

PMA Induces SnoN Proteolysis and CD61 Expression through an Autocrine Mechanism

Science.gov (United States)

Li, Chonghua; Peart, Natoya; Xuan, Zhenyu; Lewis, Dorothy E; Xia, Yang; Jin, Jianping

2014-01-01

Phorbol-12-myristate-13-acetate, also called PMA, is a small molecule that activates protein kinase C and functions to differentiate hematologic lineage cells. However, the mechanism of PMA-induced cellular differentiation is not fully understood. We found that PMA triggers global enhancement of protein ubiquitination in K562, a myelogenous leukemia cell line and one of the enhanced-ubiquitination targets is SnoN, an inhibitor of the Smad signaling pathway. Our data indicated that PMA stimulated the production of Activin A, a cytokine of the TGF-β family. Activin A then activated the phosphorylation of both Smad2 and Smad3. In consequence, SnoN is ubiquitinated by the APCCdh1 ubiquitin ligase with the help of phosphorylated Smad2. Furthermore, we found that SnoN proteolysis is important for the expression of CD61, a marker of megakaryocyte. These results indicate that protein ubiquitination promotes megakaryopoiesis via degrading SnoN, an inhibitor of CD61 expression, strengths the roles of ubiquitination in cellular differentiation. PMID:24637302

Método de ecuación por patrones para la solución de scattering electromagnético por partículas axialmente simétricas con impedancia de superficie anisotrópica compleja

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Alexander G. Kyurkchan

2013-04-01

Full Text Available El método de la ecuaciones de patrón (PEM han sido extendidospara resolver problemas de scattering en ondas electromagnéticas por medio de partículas con superficie de impedancia mista anisotrópica. Luego, las condiciones de frontera de impedancia anisotrópica se imponen en la superficie lateral de la partícula, y condiciones de frontera de impedancia isotrópica se imponen en caras finales de la partícula. El método se formula para cuerpos axialmente simétricos.Se presentan las características del scattering de los cuerpos con superficies laterales artificiales suaves y duras. Se lleva a cabo la comparación de los resultados con los que se obtienen con otros métodos. También se presenta el análisis de la tasa de convergencia del algoritmo numérico PEM y la precisión de los cálculos numéricos. Finalmente se hace la comparación de nuestros datos con los resultados numéricos obtenidos antes con el PEM en ausencia de la impedancia anisotrópica.

Organización que aprende. Caso LATU, Gerencia de Gestión Empresarial

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Gabriela Silva

2011-05-01

Full Text Available En 2001, LATU creó un departamento para brindar servicios de consultoría. Para ello, usó el conocimiento institucional y desarrolló las condiciones propicias para la creación de conocimiento interno. Dentro de las herramientas de Gestión del Conocimiento utilizadas internamente se destacan: Transferencia de personal (rotación del personal y generación de redundancia, Transferencia de experiencias ejemplares (transferencia en serie y transferencia cercana y Comunidades de práctica (grupos de mejora de procesos. Como consecuencia de cambios organizacionales en 2006, dicho servicio, junto con otros departamentos, pasó a formar parte de la Gerencia Gestión Empresarial. En la misma se complementaron las herramientas de transferencia: Transferencia lejana, Transferencia estratégica y Transferencia experta. Como parte de la transferencia de conocimiento a los clientes externos, el compromiso de la Gerencia es la utilización del conocimiento como recurso estratégico induciendo al uso de las herramientas desarrolladas realizando  más de cien proyectos en Uruguay, El Salvador, República Dominicana, México, Perú., efectivizando la transferencia de conocimiento al cliente final. AbstractIn 2001, LATU set up a department to provide consulting services. For this, used the institutional knowledge and developed the conditions for the creation of internal knowledge. Within the Knowledge Management tools used internally highlights: Transfer of personnel (Rotation of staff and Generation Redundancy , Transfer experiences copies (Serial Transfer and Transfer nearby and Communities of practice (Groups Process Improvement. As a result of organizational changes in 2006, the service, along with other departments, became part of the Business Administration Consultancy Management. In the same way were complemented transfer tools: Remote Transfer ,  Strategic Transfer andTransfer expert. As part of the knowledge transfer (consultancy to external

Activation of α7nAChR Promotes Diabetic Wound Healing by Suppressing AGE-Induced TNF-α Production.

Science.gov (United States)

Dong, Miao-Wu; Li, Ming; Chen, Jie; Fu, Tong-Tong; Lin, Ke-Zhi; Ye, Guang-Hua; Han, Jun-Ge; Feng, Xiang-Ping; Li, Xing-Biao; Yu, Lin-Sheng; Fan, Yan-Yan

2016-04-01

Diabetes frequently presents accumulation of advanced glycation end products (AGEs), which might induce excessive TNF-α production from macrophages to cause impaired wound healing. Recent studies have shown that activation of α7 nicotinic acetylcholine receptor (α7nAChR) on macrophages efficiently suppressed TNF-α synthesis. The aim of this study was to investigate the accumulation of AGEs in the wounds and determine whether PNU282987, an α7nAChR agonist, can improve wound repair by inhibiting AGE-mediated TNF-α production in a streptozotocin (STZ)-induced diabetic mouse model. Animals were assigned into four groups: wounded control group, wounded diabetic group, wounded diabetic group treated intraperitoneally with PNU282987, or wounded diabetic group treated intraperitoneally with vehicle. Compared with the non-diabetic control mice, the diabetic mice exhibited delayed wound healing that was characterized by elevated accumulation of AGEs, increased TNF-α level and macrophage infiltration, and decreased fibroblast number and collagen deposition at the late stage of repair. Besides, macrophages of diabetic wounds showed expression of α7nAChR. During late repair, PNU282987 treatment of diabetic mice significantly reduced the level of TNF-α, accelerated wound healing, and elevated fibroblast number and collagen deposition. To investigate the cellular mechanism of these observations, RAW 264.7 cells, a macrophage cell line, were incubated with AGEs in the presence or absence of PNU282987. TNF-α production from AGE-stimulated macrophages was significantly decreased by PNU282987 in a dose-dependent manner. Furthermore, PNU282987 significantly inhibited AGE-induced nuclear factor-κB (NF-κB) activation and receptor for AGE (RAGE) expression. These results strongly suggest that activating α7nAChR can promote diabetic wound healing by suppressing AGE-induced TNF-α production, which may be closely associated with the blockage of NF-κB activation in macrophages.

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilylmethylaniline with cyclic α,β-unsaturated carbonyl compounds

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Dominik Lenhart

2014-04-01

Full Text Available N-Methyl-N-((trimethylsilylmethylaniline was employed as reagent in visible-light-induced, iridium-catalyzed addition reactions to cyclic α,β-unsaturated carbonyl compounds. Typical reaction conditions included the use of one equivalent of the reaction substrate, 1.5 equivalents of the aniline and 2.5 mol % (in MeOH or 1.0 mol % (in CH2Cl2 [Ir(ppy2(dtbbpy]BF4 as the catalyst. Two major reaction products were obtained in combined yields of 30–67%. One product resulted from aminomethyl radical addition, the other product was a tricyclic compound, which is likely formed by attack of the intermediately formed α-carbonyl radical at the phenyl ring. For five-membered α,β-unsaturated lactone and lactam substrates, the latter products were the only products isolated. For the six-membered lactones and lactams and for cyclopentenone the simple addition products prevailed.

Los modelos de explotación petrolera de Ecuador y de Colombia: Un análisis desde el extractivismo y el neoextractivismo (segunda parte)

OpenAIRE

Luis Hernando Portillo Riascos

2015-01-01

En la primera parte de este trabajo se describieron los elementos conceptuales alrededor de los dos tipos o estilos de extractivismo. A la vez, se realizó una exposición de los principales cambios en el marco regulatorio del sector petrolero en los dos países analizados: Ecuador y Colombia. La segunda parte, que aquí se presenta, tiene como objetivo, hacer una revisión empírica de los dos modelos de explotación petrolera. En el análisis cuantitativo se encontró diferencias importantes en la e...

Análisis hidrodinámico de la inyección de partículas durante la refinación de plomo Análisis hidrodinámico de la inyección de partículas durante la refinación de plomo

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Antonio Romero Serrano

2012-02-01

Full Text Available Pyro-refining is one of the techniques used in recycling lead. Two significant stages in theprocess are decopperization and desilverization, which are traditionally done by addingpowdered Sulfer and Zinc at the surface of the lead bath and then mixing it with a propeller.The efficiency of this process has been improved by using a submerged lance to injectthe reactants into the interior of the lead bath, but the hydrodynamics of this new methodhas not yet been studied until now. The aim of this study was to refine the techniquesfor injecting particles into lead baths by performing mathematical simulations using theCOMSOL 3.4 software. Residence and mixing times were produced for different injectionvelocities, and the simulation results for residence times were validated by experimentaldata obtained in the laboratory.Una técnica en el reciclaje de plomo es la piro-refinación, en donde las etapas de interés son: el decobrizado y el deplatado; que consisten en adicionar azufre y zinc en polvo, respectivamente en la superficie del baño de plomo y posteriormente se agita con una hélice. Este procedimiento ineficiente, se optimizo al inyectar los reactivos a través de una lanza en el seno del baño, lo cual incremento la eficiencia del proceso. El aspecto hidrodinámico del proceso de inyección no ha sido aún estudiado, por lo que en este trabajo, se estudio el comportamiento hidrodinámico de la inyección de partículas a través de una lanza sumergida en baños de plomo mediante simulación matemática con la aplicación del software COMSOL 3.4. Se obtuvieron los tiempos de residencia y mezclado a diferentes velocidades de inyección. Los resultados del tiempo de residencia de la simulación se validaron con datos obtenidos experimentalmente en pruebas realizadas a nivel laboratorio obteniendo una buena similitud entre ambos.

Induced expression of hepatic N-methyl-D-aspartate receptor 2C subunit gene during liver enlargement induced by lead nitrate, a hepatocellular mitogen.

Science.gov (United States)

Nemoto, Kiyomitsu; Ikeda, Ayaka; Hikida, Tokihiro; Kojima, Misaki; Degawa, Masakuni

2013-02-01

We previously demonstrated the super-induced expression of the Grin2c gene encoding the N-methyl-D-aspartate receptor 2C subunit during the development of liver enlargement with hepatocellular hypertrophy induced by phenobarbital, clofibrate, or piperonyl butoxide. In the present study, we assessed whether or not Grin2c gene expression was induced during the development of chemically induced liver enlargement with hyperplasia. Male Sprague-Dawley (SD) rats, stroke-prone spontaneously hypertensive rats (SHRSPs), and SHRSP's normotensive control, Wistar-Kyoto (WKY) rats, were administered lead nitrate (LN) (0.1 mmol/kg, single i.v.), a direct inducer of liver hyperplasia, and changes in the level of Grin2c mRNA in the liver were assessed by real-time RT-PCR. The level of hepatic Grin2c mRNA was significantly higher 6-48 hr after the injection in SD rats (about 30~40- and 70-fold over the control at 6~24 hr and 48 hr, respectively) and in WKY rats (about 20-fold over the control only at 12 hr), but was not significantly higher in SHRSPs. Such differences in LN-induced levels of Grin2c mRNA among SD rats, WKY rats, and SHRSPs were closely correlated with those in the previously reported increase in liver weight 48 hr after LN administration. The present findings suggest that the increase in the level of hepatic Grin2c mRNA relates to development of chemically induced liver enlargement with hyperplasia.

Attenuation of phosphamidon-induced oxidative stress and immune dysfunction in rats treated with N-acetylcysteine

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S.G. Suke

2008-09-01

Full Text Available The effect of N-acetylcysteine, a thiolic antioxidant, on attenuation of phosphamidon-induced oxidative stress and immune dysfunction was evaluated in adult male Wistar rats weighing 200-250 g. Rats were divided into four groups, 8 animals/group, and treated with phosphamidon, N-acetylcysteine or the combination of both for 28 days. Oral administration of phosphamidon (1.74 mg/kg, an organophosphate insecticide, increased serum malondialdehyde (3.83 ± 0.18 vs 2.91 ± 0.24 nmol/mL; P < 0.05 and decreased erythrocyte superoxide dismutase (567.8 ± 24.36 vs 749.16 ± 102.61 U/gHb; P < 0.05, catalase activity (1.86 ± 0.18 vs 2.43 ± 0.08 U/gHb; P < 0.05 and whole blood glutathione levels (1.25 ± 0.21 vs 2.28 ± 0.08 mg/gHb; P < 0.05 showing phosphamidon-induced oxidative stress. Phosphamidon exposure markedly suppressed humoral immune response as assessed by antibody titer to ovalbumin (4.71 ± 0.51 vs 8.00 ± 0.12 -log2; P < 0.05, and cell-mediated immune response as assessed by leukocyte migration inhibition (25.24 ± 1.04 vs 70.8 ± 1.09%; P < 0.05 and macrophage migration inhibition (20.38 ± 0.99 vs 67.16 ± 5.30%; P < 0.05 response. Phosphamidon exposure decreased IFN-у levels (40.7 ± 3.21 vs 55.84 ± 3.02 pg/mL; P < 0.05 suggesting a profound effect of phosphamidon on cell-mediated immune response. A phosphamidon-induced increase in TNF-α level (64.19 ± 6.0 vs 23.16 ± 4.0 pg/mL; P < 0.05 suggests a contributory role of immunocytes in oxidative stress. Co-administration of N-acetylcysteine (3.5 mmol/kg, orally with phosphamidon attenuated the adverse effects of phosphamidon. These findings suggest that oral N-acetylcysteine treatment exerts protective effect and attenuates free radical injury and immune dysfunction caused by subchronic phosphamidon exposure.

Role of complex formation in the photosensitized degradation of DNA induced by N'-formylkynurenine

International Nuclear Information System (INIS)

Walrant, P.; Santus, R.; Charlier, M.

1976-01-01

N'-Formylkynurenine derivatives efficiently bind to DNA or polynucleotides. Homopolynucleotides and DNA displayed marked differences in the binding process. Association constants were derived which indicated that the oxidized indole ring is more strongly bound to DNA than the unoxidized one. Irradiation of such complexes with wavelengths greater than 320 nm induced pyrimidine dimer formation as well as DNA chain breaks. Complex formation is shown to play an important role in these photosensitized reactions. The photodynamic action of N-formylkynurenine on DNA constituents was negligible at neutral pH but guanine and xanthine derivatives were sensitizable at higher pH. Thymine dimer splitting can occur in aggregated frozen aqueous solutions of N'-formylkynurenine and thymine dimer but this photosensitized splitting was negligible in liquid solutions at room temperature. (author)

La personalidad de José Asunción Silva. (II parte

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José Francisco Socarrás

1988-08-01

Hartman, atto Kernberg y Heinz Kohut acerca de la formación del yo, del “sí mismo” y del superyo.

El ello, el yo y el superyo

Según la teoría de Freud, las instancias fundamentales de la persona son el ello, el yo y el superyo. El ello comprende lo heredado, Principalmente los instintos dependientes de la constitución somática. Contiene energías sexuales, la libido, y agresivas. Se rige, en consecuencia, por un proceso primario de impulsos contradictorios. Muchos de estos son inconscientes después de haber

sido reprimidos. La comunicación del ello con el mundo exterior se hace a través del yo. En el ello no hay distinción entre lo bueno y lo malo y provee de energía al yo y al superyo. Diversos autores han criticado el esquema instintual de Freud. Algunos lo han reducido a los instintos de vida y de muerte o tánatos. Otros han cambiado instinto por necesidad o por apetito.

El yo es la parte de la persona que actúa como agente de transacción entre el ello, el superyo, instancia represora, y el mundo exterior. Su porción preconsciente y consciente toma las decisiones y las lleva a cabo. Es catectizado por la libido y el instinto agresivo del ello con carácter narcisista secundario. Controla la motricidad voluntaria y lleva a cabo compromisos razonables entre la satisfacción de las necesidades, su represión o aplazamiento y la realidad. Adopta para el caso los llamados mecanismos de defensa.

Los principales de tales mecanismos son la represión y la negación. La represión excluye de la conciencia el deseo instintivo y sus derivados, afectos, recuerdos y fantasías asociadas. Es primaria cuando impide que derivados peligrosos del ello accedan a la conciencia, y secundaria, si no deja que reingrese a la conciencia el material que estuvo en ella. La negación o rechazo mantiene alejada de la conciencia percepciones traumáticas. Defiende pues de las exigencias de la realidad externa; caso típico el del hombre impotente que

La resolución de conflictos en el aula como parte del proceso de autonomía

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Díaz, María

2005-09-01

Full Text Available El desarrollo de la autonomía emocional y la resolución de conflictos son objetivos prioritarios para la convivencia y el crecimiento personal. A través de una observación sistemática y un modelo log-linear, este estudio muestra el bajo nivel de autonomía en los primeros ciclos de la etapa de Educación Primaria, una gran dificultad por parte de los niños para resolver conflictos y una enorme dependencia emocional y cognitiva respecto al adulto. Esto puede continuar en etapas posteriores, por eso es fundamental que, desde pequeños, los alumnos se acostumbren a enfrentarse a situaciones conflictivas, ya que éstas ayudan al proceso de diferenciación de cada individuo y al desarrollo de habilidades sociales básicas para los distintos aprendizajes y para la convivencia. Además, es necesario favorecer que los alumnos sean responsables de su proceso de aprendizaje, impulsando la capacidad de confrontación, de discusión, de pensar diferente y de valorar los acuerdos.

Test de respiración única para la capacidad de difusión de monóxido de carbono (DLCO) y su interpretación en enfermedades autoinmunes. Aplicación en la práctica clínica -Segunda Parte-

OpenAIRE

Mora Alfonso, Sergio Alexander; Bello Gualtero, Juan Manuel; Londoño, John; Valle-Oñate, Rafael Raúl; Quintana, Gerardo

2011-01-01

El test de respiración única ha probado por si mismo ser una parte esencial del tamizaje de rutina de la función pulmonar, y de igual valor que la espirometría. A pesar de 100 años de investigación, aún no existe certeza sobre la relativa importancia de las membranas alveolo-capilares vs los eritrocitos como los pasos que sean delimitantes en el transporte global del monóxido de carbono del gas hacia la sangre, pero esto es solo un problema cuantitativo. La naturaleza esencial del test de DLC...

Mapping a Part of Neuquén Basin in Argentina by Global-phase H/V Spectral Ratio

NARCIS (Netherlands)

Nishitsuji, Yohei; Ruigrok, E.N.; Gomez, M.; Draganov, Deyan

2015-01-01

We investigated the applicability of global phases (epicentral distances of ≥ 120° and ≥ 150°) for the H/V spectral ratio to identify the fundamental resonance frequency. We applied the method to delineate a part of Neuquén basin in Argentina without the need for active seismic sources. We obtained

EL español andino. II parte

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Rubén Arboleda Toro

2002-01-01

Full Text Available En el número 13 de esta revista (nov. del 2000 se publicó una primera parte del estudio sobre el español andino. Presentamos ahora una segunda parte que comprende aspectos histórico-geográficos de Nariño y Putumayo andinos, región de Colombia donde se habla esa variedad, y una descripción general de su realidad lingüística. Esperamos que sean objeto de otra publicación la descripción de los rasgos dialectales del español andino, parte nuclear del trabajo, y la presentación de la metodología y el corpus. En esto nos encontramos trabajando. Incluimos no obstante un inventario de rasgos más amplio que el presentado en la primera parte. Pero por ahora se trata de eso, de un inventario ilustrativo, no del análisis en el que estamos empeñados, en el marco del contacto de lenguas, el cambio lingüístico y la relación entre la norma y las posibilidades del sistema. Para contextualizar esta segunda parte, incluimos, a manera de introducción, un resumen de la primera.

Desarrollo y caracterización de un material compuesto de matriz de aluminio 6061 y partículas de TiB2

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Plaza, L. M.

2010-12-01

Full Text Available The incorporation of ceramic particles has been one of the ways developed to improve the mechanical properties of aluminium alloys during the last years. The main objective of this work has been to develop the manufacturing process of the reinforced aluminium alloy and analyse its mechanical properties and microstructure. Details about an innovative MMC manufacturing process and the results obtained in the development of a new family of TiB2- reinforced aluminium alloys for forging and extrusion applications are presented. It has been observed that the considered manufacturing process, consisting in the fabrication of particles by SHS and their incorporation into the selected alloy, is a feasible process to manufacture reinforced alloys that can be subsequently extruded or forged. The final result is the development of a material suitable for extrusion and forging applications and that presents an improvement of fatigue and tensile properties of the matrix alloy.Una de las vías desarrolladas, en los últimos años, para la mejora de las propiedades mecánicas de las aleaciones de aluminio es la de la incorporación de refuerzos cerámicos en forma de partículas cerámicas. El objetivo principal del trabajo ha sido desarrollar el proceso de fabricación de una aleación de aluminio 6061 reforzada con partículas de diboruro de titanio, TiB2, y analizar las propiedades del material obtenido. Se ha observado que el proceso de fabricación planteado, consistente en la fabricación de las partículas por medio del proceso de síntesis autopropagada a alta temperatura SHS (Self propagating high temperature synthesis y su posterior incorporación a la aleación 6061, es un proceso viable para la fabricación de aleaciones reforzadas adecuadas para la realización de procesos subsiguientes de extrusión o forja. El resultado final es la obtención de un material adecuado para la fabricación de componentes extruidos y que presenta una mejora de sus

Rat model hindlimb ischemia induced via embolization with polyvinyl alcohol and N butyl cyanoacrylate

Energy Technology Data Exchange (ETDEWEB)

Shin, Cheong Il; Kim, Hyo Cheol; Song, Yong Sub; Cho, Hye Rim; Lee, Kyoung Bun; Jae, Hwan June; Chung, Jin Wook [Seoul National University Hospital, Seoul (Korea, Republic of)

2013-12-15

To investigate the feasibility of a rat model on hindlimb ischemia induced by embolization from the administration of polyvinyl alcohol (PVA) particles or N-butyl cyanoacrylate (NBCA). Unilateral hindlimb ischemia was induced by embolization with NBCA (n = 4), PVA (n = 4) or surgical excision (n = 4) in a total of 12 Sprague-Dawley rats. On days 0, 7 and 14, the time-of-flight magnetic resonance angiography (TOF-MRA) and enhanced MRI were obtained as scheduled by using a 3T-MR scanner. The clinical ischemic index, volume change and degree of muscle necrosis observed on the enhanced MRI in the ischemic hindlimb were being compared among three groups using the analysis of variance. Vascular patency on TOF-MRA was evaluated and correlated with angiographic findings when using an inter-rater agreement test. There was a technical success rate of 100% for both the embolization and surgery groups. The clinical ischemic index did not significantly differ. On day 7, the ratios of the muscular infarctions were 0.436, 0.173 and 0 at thigh levels and 0.503, 0.337 and 0 at calf levels for the NBCA, PVA and surgery groups, respectively. In addition, the embolization group presented increased volume and then decreased volume on days 7 and 14, respectively. The surgery group presented a gradual volume decrease. Good correlation was shown between the TOF-MRA and angiographic findings (kappa value of 0.795). The examined hindlimb ischemia model using embolization with NBCA and PVA particles in rats is a feasible model for further research, and muscle necrosis was evident as compared with the surgical model.

Interspecific transfer of only part of genome by fusion between non-irradiated protoplasts of Nicotiana glauca and X-ray irradiated protoplasts of N. Langsdorffii

International Nuclear Information System (INIS)

Itoh, K.; Futsuhara, Y.

1983-01-01

To transfer only part of genome, X-ray irradiated suspension cell protoplasts of N. langsdorffii were fused with suspension cell protoplasts of N. glauca by polyethylene glycol. Somatic hybrid calli were selected by the growth in the hormone-free medium. Some of somatic hybrid calli from fusion with irradiated protoplasts indicated the loss of small subunit polypeptide of fraction 1 protein which was coded by N. langsdorffii nuclear DNA. Cytological analysis provided an information on significant decrease of chromosomes in somatic hybrid calli from fusion with irradiated protoplasts, compared with the somatic hybrid calli from fusion with non-irradiated protoplasts. In addition, isozyme analysis revealed that somatic hybrid calli from fusion with irradiated protoplasts lost particular bands of N. langsdorffli. These results demonstrate the tranfer of only part of genome from N, langsdorffii to N, glauca by fusion with X-ray irradiated protoplasts

Persistent and heritable structural damage induced in heterochromatic DNA from rat liver by N-nitrosodimethylamine

International Nuclear Information System (INIS)

Ward, E.J.; Stewart, B.W.

1987-01-01

Analysis, by benzoylated DEAE-cellulose chromatography, has been made of structural change in eu- and heterochromatic DNA from rat liver following administration of the carcinogen N-nitrosodimethylamine. Either hepatic DNA was prelabeled with [ 3 H]thymidine administered 2-3 weeks before injection of the carcinogen or the labeled precursor was given during regenerative hyperplasia in rats treated earlier with N-nitrosodimethylamine. Following phenol extraction of either whole liver homogenate or nuclease-fractionated eu- and heterochromatin, carcinogen-modified DNA was examined by stepwise or caffeine gradient elution from benzoylated DEAE-cellulose. In whole DNA, nitrosamine-induced single-stranded character was maximal 4-24 h after treatment, declining rapidly thereafter; gradient elution of these DNA preparations also provided short-term evidence of structural change. Caffeine gradient chromatography suggested short-term nitrosamine-induced structural change in euchromatic DNA, while increased binding of heterochromatic DNA was evident for up to 3 months after carcinogen treatment. Preparations of newly synthesized heterochromatic DNA from animals subjected to hepatectomy up to 2 months after carcinogen treatment provided evidence of heritable structural damage. Carcinogen-induced binding of heterochromatic DNA to benzoylated DEAE-cellulose was indicative of specific structural lesions whose affinity equalled that of single-stranded DNA up to 1.0 kilobase in length. The data suggest that structural lesions in heterochromatin, which may be a consequence of incomplete repair, are preferentially degraded by endogenous nuclease(s)

Effects of pilocarpine and kainate-induced seizures on N-methyl-d-aspartate receptor gene expression in the rat hippocampus

Energy Technology Data Exchange (ETDEWEB)

Przewlocka, B.; Labuz, D.; Machelska, H.; Przewlocki, R.; Turchan, J.; Lason, W. [Department of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow (Poland)

1997-04-14

The effects of pilocarpine- and kainate-induced seizures on N-methyl-d-aspartate receptor subunit-1 messenger RNA and [{sup 3}H]dizocilpine maleate binding were studied in the rat hippocampal formation. Pilocarpine- but not kainate-induced seizures decreased N-methyl-d-aspartate receptor subunit-1 messenger RNA level in dentate gyrus at 24 and 72 h after drug injection. Both convulsants decreased the messenger RNA level in CA1 pyramidal cells at 24 and 72 h, the effects of kainate being more profound. Kainate also decreased the N-methyl-d-aspartate receptor subunit-1 messenger RNA level in CA3 region after 24 and 72 h, whereas pilocarpine decreased the messenger RNA level at 72 h only. At 3 h after kainate, but not pilocarpine, an increased binding of [{sup 3}H]dizocilpine maleate in several apical dendritic fields of pyramidal cells was found. Pilocarpine reduced the [{sup 3}H]dizocilpine maleate binding in stratum lucidum only at 3 and 24 h after the drug injection. Pilocarpine but not kainate induced prolonged decrease in N-methyl-d-aspartate receptor subunit-1 gene expression in dentate gyrus. However, at the latest time measured, kainate had the stronger effect in decreasing both messenger RNA N-methyl-d-aspartate receptor subunit-1 and [{sup 3}H]dizocilpine maleate binding in CA1 and CA3 hippocampal pyramidal cells. The latter changes corresponded, however, to neuronal loss and may reflect higher neurotoxic potency of kainate.These data point to some differences in hippocampal N-methyl-d-aspartate receptor regulation in pilocarpine and kainate models of limbic seizures. Moreover, our results suggest that the N-methyl-d-aspartate receptor subunit-1 messenger RNA level is more susceptible to limbic seizures than is [{sup 3}H]dizocilpine maleate binding in the rat hippocampal formation. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

Effects of pilocarpine and kainate-induced seizures on N-methyl-d-aspartate receptor gene expression in the rat hippocampus

International Nuclear Information System (INIS)

Przewlocka, B.; Labuz, D.; Machelska, H.; Przewlocki, R.; Turchan, J.; Lason, W.

1997-01-01

The effects of pilocarpine- and kainate-induced seizures on N-methyl-d-aspartate receptor subunit-1 messenger RNA and [ 3 H]dizocilpine maleate binding were studied in the rat hippocampal formation. Pilocarpine- but not kainate-induced seizures decreased N-methyl-d-aspartate receptor subunit-1 messenger RNA level in dentate gyrus at 24 and 72 h after drug injection. Both convulsants decreased the messenger RNA level in CA1 pyramidal cells at 24 and 72 h, the effects of kainate being more profound. Kainate also decreased the N-methyl-d-aspartate receptor subunit-1 messenger RNA level in CA3 region after 24 and 72 h, whereas pilocarpine decreased the messenger RNA level at 72 h only. At 3 h after kainate, but not pilocarpine, an increased binding of [ 3 H]dizocilpine maleate in several apical dendritic fields of pyramidal cells was found. Pilocarpine reduced the [ 3 H]dizocilpine maleate binding in stratum lucidum only at 3 and 24 h after the drug injection. Pilocarpine but not kainate induced prolonged decrease in N-methyl-d-aspartate receptor subunit-1 gene expression in dentate gyrus. However, at the latest time measured, kainate had the stronger effect in decreasing both messenger RNA N-methyl-d-aspartate receptor subunit-1 and [ 3 H]dizocilpine maleate binding in CA1 and CA3 hippocampal pyramidal cells. The latter changes corresponded, however, to neuronal loss and may reflect higher neurotoxic potency of kainate.These data point to some differences in hippocampal N-methyl-d-aspartate receptor regulation in pilocarpine and kainate models of limbic seizures. Moreover, our results suggest that the N-methyl-d-aspartate receptor subunit-1 messenger RNA level is more susceptible to limbic seizures than is [ 3 H]dizocilpine maleate binding in the rat hippocampal formation. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

MK-801, but not naloxone, attenuates high-dose dextromethorphan-induced convulsive behavior: Possible involvement of the GluN2B receptor.

Science.gov (United States)

Tran, Hai-Quyen; Chung, Yoon Hee; Shin, Eun-Joo; Tran, The-Vinh; Jeong, Ji Hoon; Jang, Choon-Gon; Nah, Seung-Yeol; Yamada, Kiyofumi; Nabeshima, Toshitaka; Kim, Hyoung-Chun

2017-11-01

Dextromethorphan (DM) is a dextrorotatory isomer of levorphanol, a typical morphine-like opioid. When administered at supra-antitussive doses, DM produces psychotoxic and neurotoxic effects in humans. Although DM abuse has been well-documented, few studies have examined the effects of high-dose DM. The present study aimed to explore the effects of a single high dose of DM on mortality and seizure occurrence. After intraperitoneal administration with a high dose of DM (80mg/kg), Sprague-Dawley rats showed increased seizure occurrence and intensity. Hippocampal expression levels of N-methyl-d-aspartate (NMDA) receptor subunits (GluN1N2AN2B), c-Fos and pro-apoptotic factors (Bax and cleaved caspase-3) were upregulated by DM treatment; while levels of anti-apoptotic factors (Bcl-2 and Bcl-xL) were downregulated. Consistently, DM also induced ultrastructural degeneration in the hippocampus. A non-competitive NMDA receptor antagonist, MK-801, attenuated these effects of high-dose DM, whereas an opioid antagonist, naloxone, did not affect DM-induced neurotoxicity. Moreover, pretreatment with a highly specific GluN2B subunit inhibitor, traxoprodil, was selectively effective in preventing DM-induced c-Fos expression and apoptotic changes. These results suggest that high-dose DM produces convulsive behaviors by activating GluN2B/NMDA signaling that leads to pro-apoptotic changes. Copyright © 2017. Published by Elsevier Inc.

La belleza del mundo es la Belleza de Dios (El núcleo estético del lrtán de Ibn'Arabi IIª parte.

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José Miguel Puerta Vílchez

2001-01-01

Full Text Available We will intend to evaluate, throughout the two consecutive parts of this study, which is to be considered the status at the veiy same time hierophan¡cal and cosmological, ontological and anthropological, that the notion of Beauty invests in te speculative misticism of te andalusian Mubyi al-Din Este artículo es la ponencia presentada en ci Seminario Mu¿iyi al-Din ¡bn `Arabi -Mawldnd falal al-Din al Ram!. Dos frentes clásicaspara el estudio de la mística especulativa en el Islam, que se celebró en la Facultad de Filosofia de la Universidad Complutense, en colaboración que la Consejería Cultural de la República islámica de Irán en Madrid, durante los días ¡9,20 y 21 de enero de 1999. ¡ La primera parte de este artículo se publicó en el número anterior de esta misma Revista. 31 José Miguel Puerta Vílchez La belleza del mundo es la belleza de Dios lbn `Arabí (1165-1240, known as well as "te greatest master" in the realm of islamie spirituality. And this by conftonting the theories of islaxnic aesthetics and philosophy, and both flarthermore by clari~'ing a vocabula¡y plenty of poliedric significances and by presenting the doctrine of a creative imagination of which its noetical and sacred value will be thus explored.

Morphological mutations induced by gamma rays, ethylene imine and N-nitroso-N-ethyl urea in lentil (Lens culinaris medik.)

International Nuclear Information System (INIS)

Solanki, I.S.; Sharma, B.

2003-01-01

Dry and healthy seeds of a large seeded lentil cv, 'Precoz Selection', were treated with three doses each of gamma rays, ethylene imine (EI) and N-nitroso-N-ethyl urea (NEU). Based on the frequency of morphological mutations, the mutagens were arranged in the order: NEU > EI >. Gamma rays and dose-dependent relationship was observed in the case of gamma rays (5 kR 1 damage groups induced morphological mutations in the order: HH > HL > LH > LL. The morphological mutations included changes for growth habit, foliage, plant height and maturity and flowering behaviour. A mild relative mutagenic specificity and differences in mutability of genes for different traits were observed, In general the spectrum of morphological mutations was not influenced by the groups of M 1 damage, except that some mutation types occurred more frequently, than others in certain groups. (author)

Near infrared radiation protects against oxygen-glucose deprivation-induced neurotoxicity by down-regulating neuronal nitric oxide synthase (nNOS) activity in vitro.

Science.gov (United States)

Yu, Zhanyang; Li, Zhaoyu; Liu, Ning; Jizhang, Yunneng; McCarthy, Thomas J; Tedford, Clark E; Lo, Eng H; Wang, Xiaoying

2015-06-01

Near infrared radiation (NIR) has been shown to be neuroprotective against neurological diseases including stroke and brain trauma, but the underlying mechanisms remain poorly understood. In the current study we aimed to investigate the hypothesis that NIR may protect neurons by attenuating oxygen-glucose deprivation (OGD)-induced nitric oxide (NO) production and modulating cell survival/death signaling. Primary mouse cortical neurons were subjected to 4 h OGD and NIR was applied at 2 h reoxygenation. OGD significantly increased NO level in primary neurons compared to normal control, which was significantly ameliorated by NIR at 5 and 30 min post-NIR. Neither OGD nor NIR significantly changed neuronal nitric oxide synthase (nNOS) mRNA or total protein levels compared to control groups. However, OGD significantly increased nNOS activity compared to normal control, and this effect was significantly diminished by NIR. Moreover, NIR significantly ameliorated the neuronal death induced by S-Nitroso-N-acetyl-DL-penicillamine (SNAP), a NO donor. Finally, NIR significantly rescued OGD-induced suppression of p-Akt and Bcl-2 expression, and attenuated OGD-induced upregulation of Bax, BAD and caspase-3 activation. These results suggest NIR may protect against OGD at least partially through reducing NO production by down-regulating nNOS activity, and modulating cell survival/death signaling.

N-Methyl-d-Aspartate (NMDA Receptor Blockade Prevents Neuronal Death Induced by Zika Virus Infection

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Vivian V. Costa

2017-04-01

Full Text Available Zika virus (ZIKV infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N-methyl-d-aspartate receptor (NMDAR-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801, agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration.

Tuning the polarization-induced free hole density in nanowires graded from GaN to AlN

Science.gov (United States)

Golam Sarwar, A. T. M.; Carnevale, Santino D.; Kent, Thomas F.; Yang, Fan; McComb, David W.; Myers, Roberto C.

2015-01-01

We report a systematic study of p-type polarization-induced doping in graded AlGaN nanowire light emitting diodes grown on silicon wafers by plasma-assisted molecular beam epitaxy. The composition gradient in the p-type base is varied in a set of samples from 0.7%Al/nm to 4.95%Al/nm corresponding to negative bound polarization charge densities of 2.2 × 1018 cm-3 to 1.6 × 1019 cm-3. Capacitance measurements and energy band modeling reveal that for gradients greater than or equal to 1.30%Al/nm, the deep donor concentration is negligible and free hole concentrations roughly equal to the bound polarization charge density are achieved up to 1.6 × 1019 cm-3 at a gradient of 4.95%Al/nm. Accurate grading lengths in the p- and n-side of the pn-junction are extracted from scanning transmission electron microscopy images and are used to support energy band calculation and capacitance modeling. These results demonstrate the robust nature of p-type polarization doping in nanowires and put an upper bound on the magnitude of deep donor compensation.

Attenuation of N-nitrosodimethylamine induced hepatotoxicity by Operculina turpethum in Swiss Albino mice

Science.gov (United States)

Sharma, Veena; Singh, Manu

2014-01-01

Objective(s): To appraise the antihepatotoxic efficacy of ethanolic extract of Operculum turpethum root on the liver of Swiss albino mice. Materials and Methods: Hepatic fibrosis was induced in adult male albino mice through intraperitoneal administrations of N-nitrosodimethylamine (NDMA) at the concentration of 10 mg/kg body weight. The liver toxicity and therapeutic effect of the plant ethanolic extract was assessed by the analysis of liver marker enzymes and antioxidant enzymes and liver histopathological studies. Results: Hepatotoxicity was manifested by significantly decreased (PNDMA induced toxicity which was also supported by histopathological studies of the liver. Conclusion: O. turpethum manifested therapeutic effects by significantly restoring the enzymatic levels and reducing the hepatic damage in mice. This work intends to aid researchers in the study of natural products which could be useful in the treatment of liver diseases including cancer. PMID:24592311

Monte Carlo simulation of fission yields, kinetic energy, fission neutron spectrum and decay γ-ray spectrum for 232Th(n,f) reaction induced by 3H(d,n) 4He neutron source

International Nuclear Information System (INIS)

Zheng Wei; Zeen Yao; Changlin Lan; Yan Yan; Yunjian Shi; Siqi Yan; Jie Wang; Junrun Wang; Jingen Chen; Chinese Academy of Sciences, Shanghai

2015-01-01

Monte Carlo transport code Geant4 has been successfully utilised to study of neutron-induced fission reaction for 232 Th in the transport neutrons generated from 3 H(d,n) 4 He neutron source. The purpose of this work is to examine the applicability of Monte Carlo simulations for the computation of fission reaction process. For this, Monte Carlo simulates and calculates the characteristics of fission reaction process of 232 Th(n,f), such as the fission yields distribution, kinetic energy distribution, fission neutron spectrum and decay γ-ray spectrum. This is the first time to simulate the process of neutron-induced fission reaction using Geant4 code. Typical computational results of neutron-induced fission reaction of 232 Th(n,f) reaction are presented. The computational results are compared with the previous experimental data and evaluated nuclear data to confirm the certain physical process model in Geant4 of scientific rationality. (author)

Methyl and isopropyl N-methylanthranilates attenuate diclofenac- and ethanol-induced gastric lesions in rats.

Science.gov (United States)

Radulović, Niko S; Jovanović, Ivan; Ilić, Ivan R; Randjelović, Pavle J; Stojanović, Nikola M; Miltojević, Ana B

2013-11-19

Two natural alkaloids, methyl (M) and isopropyl (I) N-methylanthranilates, with recently demonstrated significant pharmacological activities, were assayed for their possible overall effect on intact gastric mucosa and their protective properties towards the onset of gastric lesions induced by diclofenac (a non-steroidal anti-inflammatory drug, NSAID) or ethanol. The influence of I and M on gastric mucosa integrity was assessed by oral administration in doses of 200mg/kg. The gastroprotective action of I and M in doses of 50, 100 and 200mg/kg was analyzed in the diclofenac and ethanol-induced gastric lesion models in rats. After the treatment, the stomachs of the animals were analyzed (captured by a digital camera). Ulcer scoring, morphometric and histopathological analyses of the stomachs were done. The oral application of these compounds on their own, even in quite high doses (200mg/kg) did not induce gastric lesions. Both alkaloids exerted a very strong antiulcer activity, even in low doses (50mg/kg), by decreasing the number of lesions caused by the application of either diclofenac or ethanol, eliminating them completely or reducing them to a form of mucosal hyperemia. Their possible mechanism of action was discussed and due to their many positive properties including anxiolytic, antidepressant, antinociceptive, anti-inflammatory and gastroprotective activities, as well as a cheap and simple synthetic route for their preparation, methyl and isopropyl N-methylanthranilates, both alike, might represent a cost effective alternative sought for in the treatment of peptic ulcers and/or new safer NSAIDs for pain management. © 2013.

Mutated N-ras does not induce p19 arf in CO25 cell line | Saleh ...

African Journals Online (AJOL)

The mouse cell line (CO25) used in this study was transfected with a glucocorticoid inducible mutated human N-ras oncogene under transcriptional control of the steroid-sensitive promoter of the mouse mammary tumors virus long terminal repeat MMTV-LTR. This study was aimed to investigate the expression of p19arf and ...

N=3 and N=4 superconformal WZNW sigma models in superspace. Part 1

International Nuclear Information System (INIS)

Ivanov, E.A.; Krivonos, S.O.

1989-01-01

A manifestly invariant superfield description of N=3 and N=4 2D superconformal WZNW sigma models with U(1)xO(3) and U(1)xUO(4) as the bosonic target manifolds. We construct the N=3 superspace formulation of the U(1)xO(3) model. The self-contained definition of N=3 supercurrent via the basic U(1)xO(3) model. 23 refs

Modification of strain and 2DEG density induced by wafer bending of AlGaN/GaN heterostructure: Influence of edges caused by processing

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Ashu Wang

2018-03-01

Full Text Available Due to the piezoelectricity, the density of 2DEG (NS formed in the AlGaN/GaN heterostructure can be altered when it is deformed externally, which may be exploited to develop pressure sensors and to enhance the performance of power devices by stress engineering based on the heterostructure. In this paper, a 3D electro-mechanical simulation is presented to study how the induced strains and NS for the AlGaN/GaN wafer under bending exerted uniaxial stress are influenced by the edges caused by processing: the fabrication of the mesa used for isolation, the ohmic contact metal, the gate metal, and the passivation. Results show that the influences are dependent on distance between the edges, depth of the edges, and direction of the exerted uniaxial stress.

P143 proteins from heterologous nucleopolyhedroviruses induce apoptosis in BM-N cells derived from the silkworm Bombyx mori.

Science.gov (United States)

Hamajima, Rina; Kobayashi, Michihiro; Ikeda, Motoko

2017-04-02

We previously demonstrated that ribosomal RNA (rRNA) of Bombyx mori BM-N cells is rapidly degraded upon infection with heterologous nucleopolyhedroviruses (NPVs), including Autographa californica multiple NPV (AcMNPV), Hyphantria cunea MNPV, Spodoptera exigua MNPV and S. litura MNPV, and that this response is triggered by viral P143 proteins. The transient expression of P143 proteins from heterologous NPVs was also shown to induce apoptosis and caspase-3-like protease activation in BM-N cells. In the present study, we conducted a transient expression assay using BM-N cells expressing mutant AcMNPV P143 (Ac-P143) proteins and demonstrated that five amino acid residues cooperatively participate in Ac-P143 protein-triggered apoptosis of BM-N cells. Notably, these five residues were previously shown to be required for triggering rRNA degradation in BM-N cells. As rRNA degradation in BM-N cells does not result from apoptosis, the present results suggest that Ac-P143-triggered rRNA degradation is the upstream signal for apoptosis induction in BM-N cells. We further showed that P143 protein-triggered apoptosis does not occur in S. frugiperda Sf9 or Lymantria dispar Ld652Y cells, indicating that apoptosis induction by heterologous P143 proteins is a BM-N cell-specific response. In addition, the observed induction of apoptosis in BM-N cells was found to be mediated by activation of the initiator caspase Bm-Dronc. Taken together, these results suggest that BM-N cells evolved a unique antiviral system that recognizes heterologous NPV P143 proteins to induce rRNA degradation and caspase-dependent apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Ginger attenuated di (n-butyl phthalate-induced reproductive toxicity in pubertal male rabbits

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S. S. Oda

2017-12-01

Full Text Available This study was conducted to investigate the toxic effects of di (n-butyl phthalate (DBP on reproductive functions in male rabbits and the probable protective role of ginger. Twenty rabbits were divided equally into 4 groups: control group; DBP group (520 mg/kg body weight [BW] DBP orally, DBP+ginger group (520 mg/kg BW DBP and 400 mg/kg BW ginger and ginger group (400 mg/kg BW ginger orally. Treatments were given three-times/week. After 7 wk of the experiment, DBP induced significant reduction in testis and prostate weights, serum and intratesticular testosterone concentrations, sperm counts both mass and progressive sperm motility and live sperms percentage as well as significant elevation of testicular malondialdehyde compared to control group. No significant changes were detected in epididymal weights, serum FSH and serum LH concentrations and testicular total superoxide dismutase and glutathione peroxidase activities in all treated groups. DBP induced considerable histopathological alterations in testis and to minimal extent in epididymis and prostates. Ginger treatment attenuated the significant changes to a certain extent induced by DBP intoxication in male rabbits probably due to its potential to scavenge free radicals.

Reglamentación fiscal sobre precios de transferencia entre partes relacionadas: perspectiva de la problemática internacional y de México

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Martha Luisa Puente Esparza

2016-02-01

Full Text Available en el marco de la apertura comercial y de la gran afluencia de inversión extranjera directa (ied, se propicia la incorporación de México a la organización para la Cooperación y desarrollo económico(ocde para atraerla, adquiriendo con ello  el compromiso de aceptar sus lineamientos sobre las operaciones entre partes relacionadas y los precios de transferencia, cuyo objetivo es regular las estrategias comerciales que los grupos multinacionales utilizan para incrementar sus rendimientos; esto lo realizan por medio de la fijación de los precios entre compañías del grupo, evadiendo o eludiendo el pago de los impuestos correspondientes en el lugar donde se originan los ingresos. El objetivo de esta investigación es establecer si, en el país, la normatividad tributaria sobre precios de transferencia para este tipo de operaciones ha logrado evitar la evasión o elusión de las empresas que operan en el marco de grupos multinacionales. Por otra parte, se analizan los estudios efectuados por los organismos internacionales sobre el tema de la efectividad de esta normatividad, coincidentes en la gran influencia e importancia que ejercen los países desarrollados y su inversión en economías en vías de desarrollo.

Solar UV irradiation-induced production of N2O from plant surfaces - low emissions rates but all over the world.

Science.gov (United States)

Mikkelsen, T. N.; Bruhn, D.; Ambus, P.

2016-12-01

Nitrous oxide (N2O) is an important long-lived greenhouse gas and precursor of stratospheric ozone depleting mono-nitrogen oxides. The atmospheric concentration of N2O is persistently increasing; however, large uncertainties are associated with the distinct source strengths. Here we investigate for the first time N2O emission from terrestrial vegetation in response to natural solar ultra violet radiation. We conducted field site measurements to investigate N2O atmosphere exchange from grass vegetation exposed to solar irradiance with and without UV-screening. Further laboratory tests were conducted with a range of species to study the controls and possible loci of UV-induced N2O emission from plants. Plants released N2O in response to natural sunlight at rates of c. 20-50 nmol m-2 h-1, mostly due to the UV component. The emission rate is temperature dependent with a rather high activation energy indicative for an abiotic process. The prevailing zone for the N2O formation appears to be at the very surface of leaves. However, only c. 26% of the UV-induced N2O appears to originate from plant-N. Further, the process is dependent on atmospheric oxygen concentration. Our work demonstrates that ecosystem emission of the important greenhouse gas, N2O, may be up to c. 30% higher than hitherto assumed.

60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

International Nuclear Information System (INIS)

Wang Yanping; Luo Yinhong; Wang Wei; Zhang Keying; Guo Hongxia; Guo Xiaoqiang; Wang Yuanming

2013-01-01

The testing techniques and experimental methods of the 60 Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established. The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically, and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out. The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated, and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained. (authors)

Resveratrol alleviates diabetes-induced testicular dysfunction by inhibiting oxidative stress and c-Jun N-terminal kinase signaling in rats

Energy Technology Data Exchange (ETDEWEB)

Faid, Iman; Al-Hussaini, Heba; Kilarkaje, Narayana, E-mail: knarayana@hsc.edu.kw

2015-12-15

Diabetes adversely affects reproductive functions in humans and animals. The present study investigated the effects of Resveratrol on diabetes-induced alterations in oxidative stress, c-Jun N-terminal kinase (JNK) signaling and apoptosis in the testis. Adult male Wistar rats (13–15 weeks; n = 6/group) were segregated into 1) normal control, 2) Resveratrol-treated (5 mg/kg; ip; given during last 3 weeks), 3) Streptozotocin-induced diabetic and, 4) Resveratrol-treated diabetic groups, and euthanized on day 42 after the confirmation of diabetes. Resveratrol did not normalize blood glucose levels in diabetic rats. Resveratrol supplementation recovered diabetes-induced decreases in reproductive organ weights, sperm count and motility, intra-testicular levels of superoxide dismutase, catalase, and glutathione peroxidase and an increase in 4-hydroxynonenal activities (P < 0.05). Resveratrol also recovered diabetes-induced increases in JNK signaling pathway proteins, namely, ASK1 (apoptosis signal-regulating kinase 1), JNKs (46 and 54 kDa isoforms) and p-JNK to normal control levels (P < 0.05). Interestingly, the expression of a down-stream target of ASK1, MKK4 (mitogen-activated protein kinase kinase 4) and its phosphorylated form (p-MKK4) did not change in experimental groups. Resveratrol inhibited diabetes-induced increases in AP-1 (activator protein-1) components, c-Jun and ATF2 (activating transcription factor 2), but not their phosphorylated forms, to normal control levels (P < 0.05). Further, Resveratrol inhibited diabetes-induced increase in cleaved-caspase-3 to normal control levels. In conclusion, Resveratrol alleviates diabetes-induced apoptosis in testis by modulating oxidative stress, JNK signaling pathway and caspase-3 activities, but not by inhibiting hyperglycemia, in rats. These results suggest that Resveratrol supplementation may be a useful strategy to treat diabetes-induced testicular dysfunction. - Highlights: • Resveratrol up-regulates glutathione

Resveratrol alleviates diabetes-induced testicular dysfunction by inhibiting oxidative stress and c-Jun N-terminal kinase signaling in rats

International Nuclear Information System (INIS)

Faid, Iman; Al-Hussaini, Heba; Kilarkaje, Narayana

2015-01-01

Diabetes adversely affects reproductive functions in humans and animals. The present study investigated the effects of Resveratrol on diabetes-induced alterations in oxidative stress, c-Jun N-terminal kinase (JNK) signaling and apoptosis in the testis. Adult male Wistar rats (13–15 weeks; n = 6/group) were segregated into 1) normal control, 2) Resveratrol-treated (5 mg/kg; ip; given during last 3 weeks), 3) Streptozotocin-induced diabetic and, 4) Resveratrol-treated diabetic groups, and euthanized on day 42 after the confirmation of diabetes. Resveratrol did not normalize blood glucose levels in diabetic rats. Resveratrol supplementation recovered diabetes-induced decreases in reproductive organ weights, sperm count and motility, intra-testicular levels of superoxide dismutase, catalase, and glutathione peroxidase and an increase in 4-hydroxynonenal activities (P < 0.05). Resveratrol also recovered diabetes-induced increases in JNK signaling pathway proteins, namely, ASK1 (apoptosis signal-regulating kinase 1), JNKs (46 and 54 kDa isoforms) and p-JNK to normal control levels (P < 0.05). Interestingly, the expression of a down-stream target of ASK1, MKK4 (mitogen-activated protein kinase kinase 4) and its phosphorylated form (p-MKK4) did not change in experimental groups. Resveratrol inhibited diabetes-induced increases in AP-1 (activator protein-1) components, c-Jun and ATF2 (activating transcription factor 2), but not their phosphorylated forms, to normal control levels (P < 0.05). Further, Resveratrol inhibited diabetes-induced increase in cleaved-caspase-3 to normal control levels. In conclusion, Resveratrol alleviates diabetes-induced apoptosis in testis by modulating oxidative stress, JNK signaling pathway and caspase-3 activities, but not by inhibiting hyperglycemia, in rats. These results suggest that Resveratrol supplementation may be a useful strategy to treat diabetes-induced testicular dysfunction. - Highlights: • Resveratrol up-regulates glutathione

Laser-induced breakdown spectroscopy (LIBS), part II: review of instrumental and methodological approaches to material analysis and applications to different fields.

Science.gov (United States)

Hahn, David W; Omenetto, Nicoló

2012-04-01

The first part of this two-part review focused on the fundamental and diagnostics aspects of laser-induced plasmas, only touching briefly upon concepts such as sensitivity and detection limits and largely omitting any discussion of the vast panorama of the practical applications of the technique. Clearly a true LIBS community has emerged, which promises to quicken the pace of LIBS developments, applications, and implementations. With this second part, a more applied flavor is taken, and its intended goal is summarizing the current state-of-the-art of analytical LIBS, providing a contemporary snapshot of LIBS applications, and highlighting new directions in laser-induced breakdown spectroscopy, such as novel approaches, instrumental developments, and advanced use of chemometric tools. More specifically, we discuss instrumental and analytical approaches (e.g., double- and multi-pulse LIBS to improve the sensitivity), calibration-free approaches, hyphenated approaches in which techniques such as Raman and fluorescence are coupled with LIBS to increase sensitivity and information power, resonantly enhanced LIBS approaches, signal processing and optimization (e.g., signal-to-noise analysis), and finally applications. An attempt is made to provide an updated view of the role played by LIBS in the various fields, with emphasis on applications considered to be unique. We finally try to assess where LIBS is going as an analytical field, where in our opinion it should go, and what should still be done for consolidating the technique as a mature method of chemical analysis. © 2012 Society for Applied Spectroscopy

Density distribution of currents induced inside the brain in the head part of the human model exposed to power frequency electric field

Energy Technology Data Exchange (ETDEWEB)

Chiba, Atsuo [Yongo National Collage of Technology (Japan); Isaka, Katsuo [University of Tokushima (Japan)

1999-07-01

The health effect of the weak current induced in the human body as a result of the interaction between human body and power frequency electric fields has been investigated. However, the current density inside the head part tissues of the human body exposed to the electric fields has rarely been discussed. In this paper, the finite element method is applied to the analysis of the current density distribution of the head part composed of scalp, skull, cerebrospinal liquid and brain tissues. The basic characteristics of the current density distributions of the brain in the asymmetrical human model have been made clear. (author)

Aspectos básicos de la fijación de nitrógeno atmosférico por parte de bacterias. Estudio en el laboratorio de educación secundaria

Directory of Open Access Journals (Sweden)

José Pedro López Pérez

2016-01-01

Full Text Available La fijación de nitrógeno atmosférico por parte de microorganismos tiene notable importancia ambiental e industrial relacionada con el incremento de la fertilidad y productividad en los suelos, soporte de las plantas y las redes tróficas derivadas. En el presente artículo se especifica un sencillo protocolo de laboratorio, junto con la base teórica que lo sustenta, con el objetivo de observar los microorganismos responsables de la fijación en los nódulos de leguminosas.

Capsaicin-induced neurogenic inflammation in pig skin: A behavioural study

DEFF Research Database (Denmark)

di Giminiani, Pierpaolo; Petersen, Lars Jelstrup; Herskin, Mette S

2014-01-01

Topical capsaicin is a well-established model of experimental hyperalgesia. Its application to the study of animals has been limited to few species. The effect of topical capsaicin on hyperalgesia in porcine skin was evaluated as part of a study of inflammatory pain in the pig. Two experiments were...... carried out on pigs of 27 ± 5 kg (n = 8) and 57 ± 3 kg (n = 16). Thermal and mechanical noxious stimuli were provided (CO2 laser and Pressure Application Measurement device) to assess avoidance behaviours. Capsaicin induced significant thermal hyperalgesia in the smaller pigs (P

Determination of the fast-neutron-induced fission cross-section of 242Pu at nELBE

Science.gov (United States)

Kögler, Toni; Beyer, Roland; Junghans, Arnd R.; Schwengner, Ronald; Wagner, Andreas

2018-03-01

The fast-neutron-induced fission cross section of 242Pu was determined in the energy range of 0.5 MeV to 10MeV at the neutron time-of-flight facility nELBE. Using a parallel-plate fission ionization chamber this quantity was measured relative to 235U(n,f). The number of target nuclei was thereby calculated by means of measuring the spontaneous fission rate of 242Pu. An MCNP 6 neutron transport simulation was used to correct the relative cross section for neutron scattering. The determined results are in good agreement with current experimental and evaluated data sets.

Ammonium-induced calcium mobilization in 1321N1 astrocytoma cells

International Nuclear Information System (INIS)

Hillmann, Petra; Koese, Meryem; Soehl, Kristina; Mueller, Christa E.

2008-01-01

High blood levels of ammonium/ammonia (NH 4 + /NH 3 ) are associated with severe neurotoxicity as observed in hepatic encephalopathy (HE). Astrocytes are the main targets of ammonium toxicity, while neuronal cells are less vulnerable. In the present study, an astrocytoma cell line 1321N1 and a neuroblastoma glioma hybrid cell line NG108-15 were used as model systems for astrocytes and neuronal cells, respectively. Ammonium salts evoked a transient increase in intracellular calcium concentrations ([Ca 2+ ] i ) in astrocytoma (EC 50 = 6.38 mM), but not in NG108-15 cells. The ammonium-induced increase in [Ca 2+ ] i was due to an intracellular effect of NH 4 + /NH 3 and was independent of extracellular calcium. Acetate completely inhibited the ammonium effect. Ammonium potently reduced calcium signaling by G q protein-coupled receptors (H 1 and M3) expressed on the cells. Ammonium (5 mM) also significantly inhibited the proliferation of 1321N1 astrocytoma cells. While mRNA for the mammalian ammonium transporters RhBG and RhCG could not be detected in 1321N1 astrocytoma cells, both transporters were expressed in NG108-15 cells. RhBG and RhBC in brain may promote the excretion of NH 3 /NH 4 + from neuronal cells. Cellular uptake of NH 4 + /NH 3 was mainly by passive diffusion of NH 3 . Human 1321N1 astrocytoma cells appear to be an excellent, easily accessible human model for studying HE, which can substitute animal studies, while NG108-15 cells may be useful for investigating the role of the recently discovered Rhesus family type ammonium transporters in neuronal cells. Our findings may contribute to the understanding of pathologic ammonium effects in different brain cells, and to the treatment of hyperammonemia

Evaluación de una Experiencia Partícipe de Capacitación en Evaluación de Programas Para Organizaciones Comunitarias en Puerto Rico Evaluation of a Participatory Training Experience in Program Evaluation for Community Organizations in Puerto Rico

OpenAIRE

Irma Serrano-García; Josephine Resto-Olivo; Nelson Varas-Díaz

2004-01-01

Implantamos y evaluamos un modelo de capacitación partícipe (MCP) en evaluación de programas con organizaciones comunitarias (OC) que ofrecen servicios de VIH/SIDA a diversas poblaciones incluyendo jóvenes. El MCP incluye cuatro fases: a) identificación de expectativas, necesidades y recursos (ENR), b) adiestramiento, c) evaluación de proceso e impacto, y d) seguimiento. En la primera fase entrevistamos a 30 participantes. La segunda fase incluyó talleres, consultoría y la evaluación del MCP....

Prolactin, TNF alpha and nitric oxide expression in nitroso-N-methylurea-induced-mammary tumours

Directory of Open Access Journals (Sweden)

Vegh Irene

2007-11-01

Full Text Available Abstract Background The N-Nitrosomethylurea breast cancer model induced in rats is used for the study of carcinogenesis in mammary cancer, prostate, pancreas, etc. This model is very similar to human neoplastic disease. Methods The present experimental study was designed to assess whether metoclopramide administration has any effect on development of MNU-induced tumours, and evaluate the treatment of goserelin acetate on PRL, TNF alpha and NO expression. NMU was administered to female Wistar rats on 2 occasions (5 mg/100 g body w/rat. PRL and TNF alpha were performed by immune-assay. Nitric Oxide by semi automated-assay and ploidy analyses by flow cytometry. Results The administration of metoclopramide made the induction time shorter and increased the incidence and average of tumours per rat. Tumours development was inhibited by a goserelin chronic administration. The ploidy of adenocarcinoma was polyploid-aneuploid type (average S = 60%. It was higher basal PRL plasma levels in rats with NMU induced tumours than in basal controls without tumour (p Conclusion The increase of blood PRL levels in NMU-induced rats may be an indicator of a poor prognosis of mammary cancer evolution. The metoclopramide administration accelerates tumour growth. However goserelin administration achieves regression in tumour development associated to inhibition PRL, TNF alpha and NO expression.

Effect of simultaneous vaccination with H1N1 and GAD-alum on GAD65-induced immune response.

Science.gov (United States)

Tavira, Beatriz; Cheramy, Mikael; Axelsson, Stina; Åkerman, Linda; Ludvigsson, Johnny; Casas, Rosaura

2017-07-01

A European Phase III trial of GAD formulated with aluminium hydroxide (GAD-alum) failed to reach its primary endpoint (preservation of stimulated C-peptide secretion from baseline to 15 months in type 1 diabetes patients), but subgroup analysis showed a clinical effect when participants from Nordic countries were excluded, raising concern as to whether the mass vaccination of the Swedish and Finnish populations with the Pandemrix influenza vaccine could have influenced the study outcomes. In the current study, we aimed to assess whether Pandemrix vaccination affects the specific immune responses induced by GAD-alum and the C-peptide response. In this secondary analysis, we analysed data acquired from the Swedish participants in the Phase III GAD-alum trial who received subcutaneous GAD-alum vaccination (two doses, n = 43; four doses, n = 46) or placebo (n = 48). GAD autoantibodies (GADA) and H1N1 autoantibodies, GAD 65 -induced cytokine secretion and change in fasting and stimulated C-peptide levels from baseline to 15 months were analysed with respect to the relative time between H1N1 vaccination and the first injection of GAD-alum. GADA levels at 15 months were associated with the relative time between GAD-alum and Pandemrix administration in participants who received two doses of the GAD-alum vaccine (p = 0.015, r = 0.4). Both in participants treated with two doses and four doses of GAD-alum, GADA levels were higher when the relative time between vaccines was ≥210 days (p < 0.05). In the group that received two doses of GAD-alum, levels of several GAD 65 -induced cytokines were higher in participants who received the H1N1 vaccination and the first GAD-alum injection at least 150 days apart, and the change in fasting and stimulated C-peptide at 15 months was associated with the relative time between vaccines. Neither of these effects were observed in individuals who received four doses of GAD-alum. In individuals who received two doses of GAD

Juhan Parts : Eesti saab uued ministrid paari-kolme nädalaga / Juhan Parts ; interv. Toomas Sildam

Index Scriptorium Estoniae

Parts, Juhan, 1966-

2003-01-01

Res Publica esimees Juhan Parts tunnistab Reformierakonna ja Rahvaliiduga peetavate võimukõneluste takerdumist päevaprobleemidesse, kuid loodab aprilli esimeseks pooleks valitsuskoalitsiooni kokku saada. Vt. samas: Parts kohtus Rüütliga

Use of rubber shreds to enhance attenuation of railway sub-ballast layers made of unbound aggregates; Uso de partículas de caucho para mejorar la capacidad de atenuación de capas granulares de subbalasto en ferrocarriles

Energy Technology Data Exchange (ETDEWEB)

Hidalgo-Signes, C.; Garzón-Roca, J.; Grima-Palop, J.M.; Insa-Franco, R.

2017-07-01

One of the approaches for solving the problem of induced vibrations in railways is by slightly modifying the materials that form the track. A study is presented of the attenuation capacity of mixes composed of granular soil and rubber shreds when used as sub-ballast (the layer located immediately below the ballast layer). Rubber shreds are obtained from scrap tyres, a troublesome waste material whose reuse and recycling is necessary. A series of mixes of granular soil and rubber shreds with rubber contents of between 1% and 10% are submitted to hammer impact tests to study their response to dynamic excitation. Results reveal that mixing rubber shreds with granular soil increases damping ratios, thus demonstrating the potential of the proposed mixes for attenuating vibration. [Spanish] Una de las posibles formas de resolver el problema de las vibraciones inducidas por el ferrocarril es llevando a cabo una ligera modificación de los materiales que forman la vía. En este artículo, se presenta un estudio de la capacidad de atenuación de mezclas compuestas por zahorras y partículas de caucho para ser usadas como sub-balasto (capa localizada bajo el balasto). Las partículas de caucho se obtienen a partir de neumáticos fuera de uso, un material problemático cuya reutilización y reciclaje es cada vez más necesario. Las mezclas de zahorra-caucho, con un contenido entre el 1% y 10%, se someten a una serie de ensayos dinámicos mediante impacto con martillo, estudiando su respuesta frente a la excitación dinámica. Los resultados revelan que la mezcla de partículas de caucho con zahorras aumenta el coeficiente de amortiguamiento, lo que muestra el potencial que poseen las mezclas propuestas para la atenuación de vibraciones.

Oligosaccharide modification by N-acetylglucosaminyltransferase-V in macrophages are involved in pathogenesis of bleomycin-induced scleroderma.

Science.gov (United States)

Kato, Arisa; Yutani, Mizuki; Terao, Mika; Kimura, Akihiro; Itoi, Saori; Murota, Hiroyuki; Miyoshi, Eiji; Katayama, Ichiro

2015-08-01

Oligosaccharide modification by N-acetylglucosaminyltransferase-V (GnT-V), which catalyses the formation of β1,6 GlcNAc (N-acetylglucosamine) branches on N-glycans, is associated with various pathologies, such as cancer metastasis, multiple sclerosis and liver fibrosis. In this study, we demonstrated the involvement of GnT-V in the pathophysiology of scleroderma. High expression of GnT-V was observed in infiltrating cells in skin section samples from systemic and localized patients with scleroderma. Most of the infiltrating cells were T cells and macrophages, most of which were CD163(+) M2 macrophages. To determine the role of GnT-V in scleroderma, we next investigated skin sclerosis in GnT-V knockout (MGAT5(-/-) ) mice. Expression of GnT-V was also elevated in bleomycin (BLM)-injected sclerotic skin, and MGAT5(-/-) mice were resistant to BLM-induced skin sclerosis with reduced collagen type 1 α1 content, suggesting the biological significance of GnT-V in skin sclerosis. Furthermore, the number of CD163(+) M2 macrophages and CD3-positive T cells in BLM-induced skin sclerosis was significantly fewer in MGAT5(-/-) mice. In bone marrow-derived macrophages (BMDMs), IL-4-induced expressions of Fizz1 and Ym1 were significantly reduced in MGAT5(-/-) mice-derived BMDMs. Taken together, these results suggest the induction of GnT-V in skin sclerosis progression is possibly dependent on increased numbers of M2 macrophages in the skin, which are important for tissue fibrosis and remodelling. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Benzofuroxan derivatives N-Br and N-I induce intrinsic apoptosis in melanoma cells by regulating AKT/BIM signaling and display anti metastatic activity in vivo

International Nuclear Information System (INIS)

Farias, C. F.; Massaoka, M. H.; Girola, N.; Azevedo, R. A.; Ferreira, A. K.; Jorge, S. D.; Tavares, L. C.; Figueiredo, C. R.; Travassos, L. R.

2015-01-01

Malignant melanoma is an aggressive type of skin cancer, and despite recent advances in treatment, the survival rate of the metastatic form remains low. Nifuroxazide analogues are drugs based on the substitution of the nitrofuran group by benzofuroxan, in view of the pharmacophore similarity of the nitro group, improving bioavailability, with higher intrinsic activity and less toxicity. Benzofuroxan activity involves the intracellular production of free-radical species. In the present work, we evaluated the antitumor effects of different benzofuroxan derivatives in a murine melanoma model. B16F10-Nex2 melanoma cells were used to investigate the antitumor effects of Benzofuroxan derivatives in vitro and in a syngeneic melanoma model in C57Bl/6 mice. Cytotoxicity, morphological changes and reactive oxygen species (ROS) were assessed by a diphenyltetrasolium reagent, optical and fluorescence microscopy, respectively. Annexin-V binding and mitochondrial integrity were analyzed by flow cytometry. Western blotting and colorimetry identified cell signaling proteins. Benzofuroxan N-Br and N-I derivatives were active against murine and human tumor cell lines, exerting significant protection against metastatic melanoma in a syngeneic model. N-Br and N-I induce apoptosis in melanoma cells, evidenced by specific morphological changes, DNA condensation and degradation, and phosphatidylserine translocation in the plasma membrane. The intrinsic mitochondrial pathway in B16F10-Nex2 cells is suggested owing to reduced outer membrane potential in mitochondria, followed by caspase −9, −3 activation and cleavage of PARP. The cytotoxicity of N-Br and N-I in B16F10-Nex2 cells is mediated by the generation of ROS, inhibited by pre-incubation of the cells with N-acetylcysteine (NAC). The induction of ROS by N-Br and N-I resulted in the inhibition of AKT activation, an important molecule related to tumor cell survival, followed by upregulation of BIM. We conclude that N-Br and N-I are

Benzofuroxan derivatives N-Br and N-I induce intrinsic apoptosis in melanoma cells by regulating AKT/BIM signaling and display anti metastatic activity in vivo.

Science.gov (United States)

Farias, C F; Massaoka, M H; Girola, N; Azevedo, R A; Ferreira, A K; Jorge, S D; Tavares, L C; Figueiredo, C R; Travassos, L R

2015-10-27

Malignant melanoma is an aggressive type of skin cancer, and despite recent advances in treatment, the survival rate of the metastatic form remains low. Nifuroxazide analogues are drugs based on the substitution of the nitrofuran group by benzofuroxan, in view of the pharmacophore similarity of the nitro group, improving bioavailability, with higher intrinsic activity and less toxicity. Benzofuroxan activity involves the intracellular production of free-radical species. In the present work, we evaluated the antitumor effects of different benzofuroxan derivatives in a murine melanoma model. B16F10-Nex2 melanoma cells were used to investigate the antitumor effects of Benzofuroxan derivatives in vitro and in a syngeneic melanoma model in C57Bl/6 mice. Cytotoxicity, morphological changes and reactive oxygen species (ROS) were assessed by a diphenyltetrasolium reagent, optical and fluorescence microscopy, respectively. Annexin-V binding and mitochondrial integrity were analyzed by flow cytometry. Western blotting and colorimetry identified cell signaling proteins. Benzofuroxan N-Br and N-I derivatives were active against murine and human tumor cell lines, exerting significant protection against metastatic melanoma in a syngeneic model. N-Br and N-I induce apoptosis in melanoma cells, evidenced by specific morphological changes, DNA condensation and degradation, and phosphatidylserine translocation in the plasma membrane. The intrinsic mitochondrial pathway in B16F10-Nex2 cells is suggested owing to reduced outer membrane potential in mitochondria, followed by caspase -9, -3 activation and cleavage of PARP. The cytotoxicity of N-Br and N-I in B16F10-Nex2 cells is mediated by the generation of ROS, inhibited by pre-incubation of the cells with N-acetylcysteine (NAC). The induction of ROS by N-Br and N-I resulted in the inhibition of AKT activation, an important molecule related to tumor cell survival, followed by upregulation of BIM. We conclude that N-Br and N-I are

Higgs amplitudes from supersymmetric form factors Part II: $\\mathcal{N}<4$ super Yang-Mills arXiv

CERN Document Server

Brandhuber, Andreas; Penante, Brenda; Travaglini, Gabriele

The study of form factors has many phenomenologically interesting applications, one of which is Higgs plus gluon amplitudes in QCD. Through effective field theory techniques these are related to form factors of various operators of increasing classical dimension. In this paper we extend our analysis of the first finite top-mass correction, arising from the operator ${\\rm Tr} (F^3)$, from $\\mathcal{N}=4$ super Yang-Mills to theories with $\\mathcal{N}<4$, for the case of three gluons and up to two loops. We confirm our earlier result that the maximally transcendental part of the associated Catani remainder is universal and equal to that of the form factor of a protected trilinear operator in the maximally supersymmetric theory. The terms with lower transcendentality deviate from the $\\mathcal{N}=4$ answer by a surprisingly small set of terms involving for example $\\zeta_2$, $\\zeta_3$ and simple powers of logarithms, for which we provide explicit expressions.

Defect-induced Au precipitation in Fe–Au and Fe–Au–B–N alloys studied by in situ small-angle neutron scattering

International Nuclear Information System (INIS)

Zhang, S.; Kohlbrecher, J.; Tichelaar, F.D.; Langelaan, G.; Brück, E.; Zwaag, S. van der; Dijk, N.H. van

2013-01-01

Nanoscale Au precipitation in high-purity Fe–Au and Fe–Au–B–N alloys has been studied by in situ small-angle neutron scattering during isothermal aging at 550 °C and complementary ex situ transmission electron microscopy. The high temperature precipitation behavior in samples having received different degrees of cold deformation has been studied to explore the potential self-healing of deformation-induced defects by Au precipitation. It is found that dislocations induced by prior plastic deformation strongly facilitate the formation of Au precipitates, as no significant precipitation is observed for undeformed samples. Defect-induced Au precipitates are formed both at dislocations and along grain boundaries where the defect density is high. The fact that the Au atoms only precipitate on deformation-induced defects demonstrates that solute gold atoms act as efficient self-healing agents in the ferrous matrix. The addition of B and N is found to retard the Au precipitation

EVALUACIÓN DE PROPIEDADES ANTIOXIDANTES DE PARTE COMESTIBLE Y NO COMESTIBLE DE PITAHAYA, UCHUVA Y MANGOSTINO

Directory of Open Access Journals (Sweden)

LUIS DANIEL DAZA

2014-06-01

Full Text Available En este trabajo se evaluó el contenido de fenoles en los macerados etanólicos provenientes de la parte comestible (pulpa y no comestible (semilla y cáscara de Pitahaya (Cereus triangularis, Uchuva (Physalis peruviana y Mangostino (Garcinia mangostana. Además se estudió comparativamente el potencial de los extractos para inhibir la peroxidación lipídica en una mantequilla elaborada artesanalmente. La concentración de compuestos fenólicos en la cáscara de Garcinia mangostana (590,9±3,9 mg EAG/g, resultó ser la más elevada entre los materiales analizados, contradictoriamente la pulpa de este fruto fue la porción con el contenido de fenoles (55,5±07 mg EAG/g. La actividad antioxidante mostró una relación directa con el contenido de compuesto fenólicos, con valores de coeficiente de correlación de 0,988, 0,961 y 0,998 para la Uchuva, Pitahaya y el Mangostino respectivamente. Todos los extractos mostraron actividad frente a la peroxidación lipídica y tres de ellos, cáscara de mangostino (CM, semilla de mangostino (SM y pulpa de Uchuva (PU mostraron mayor inhibición que el BHT, A.A y PC1 (producto comercial 1, mostrándose como materias primas promisorias para el uso en la industria alimentaria y cosmetica.

Comportamiento frente a la corrosión del material compuesto 2124/SiC

Directory of Open Access Journals (Sweden)

López-Caballero, J. A.

2005-12-01

Full Text Available A comparative study was performed on the corrosion behaviour of an aluminium matrix composite reinforced with silicon carbide particles, obtained by powder metallurgic. The 2124/SiC material was heat treated using T4 and T6 procedures. The T6 heat treatment induced the formation of several intermetallics and reducing the corrosion resistance. The silicon carbide particles did not have a cathodic behaviour as compared with the aluminium matrix. However, these particles produced a diminution in the corrosion resistance due to the formation of more active zones in the matrix/reinforced interface. These ceramic particles caused intermetallic precipitation and deformation originating in the surrounding zones localized corrosion.

Se realiza un estudio comparativo del comportamiento frente a la corrosión de la aleación de aluminio 2124 reforzada con partículas de carburo de silicio, obtenida por pulvimetalurgia y con tratamientos térmicos T4 y T6. Los resultados experimentales muestran que el tratamiento térmico T6 induce la formación de numerosos intermetálicos que reducen la resistencia a la corrosión. Las partículas de carburo de silicio no tienen un comportamiento catódico con respecto a la matriz de aluminio, sin embargo, disminuyen la resistencia a la corrosión, ya que generan zonas más activas en la interfase matriz/ refuerzo, debido a la acumulación de dislocaciones, tensiones residuales y a la precipitación de intermetálicos.

N-nitrosamines induced infertility and hepatotoxicity in male rabbits.

Science.gov (United States)

Sheweita, S A; El Banna, Y Y; Balbaa, M; Abdullah, I A; Hassan, H E

2017-09-01

fibrosis around portal areas were seen in hepatic tissues. In the testes, histopathological examination displayed disorganized seminiferous tubules with degeneration of germinal epithelium and Sertoli cells. Also, spermatogenic cells had pyknotic nuclei and others were detached from basement membranes of seminiferous tubules, edema was seen between seminiferous tubules. Moreover, the present data showed that MEN and DEN down-regulated the protein expression of both CYP19A1 and 21A2 in both livers and testes of male rabbits. In addition, both MEN and DEN decreased levels of testosterone and estradiol in plasma of treated rabbits. On the one hand, DMN and DPN markedly up-regulated the protein expression of CYP19A1 in both hepatic and testicular tissues of treated rabbits. These compounds potentially increased estradiol and decreased testosterone levels. On the other hand, no correlation was found between the expression of CYP11A1 and levels of both testosterone and estradiol. It is concluded that most of tested N-nitrosamines induce different changes, which could be a new mechanism of infertility due to exposure to N-nitrosamines from different environmental sources. © 2017 Wiley Periodicals, Inc.

Advice Complexity of the Online Induced Subgraph Problem

DEFF Research Database (Denmark)

Komm, Dennis; Královič, Rastislav; Královič, Richard

2016-01-01

of the input can influence the solution quality. We evaluate the information in a quantitative way by considering the best possible advice of given size that describes the unknown input. Using a result from Boyar et al. we give a tight trade-off relationship stating that, for inputs of length n, roughly n...... subgraph problem, preemption does not significantly help by giving a lower bound of Omega(n/(c^2\\log c)) on the bits of advice that are needed to obtain competitive ratio c, where c is any increasing function bounded from above by \\sqrt{n/\\log n}. We also give a linear lower bound for c close to 1....... these problems by investigating a generalized problem: for an arbitrary but fixed hereditary property, find some maximal induced subgraph having the property. We investigate this problem from the point of view of advice complexity, i.e. we ask how some additional information about the yet unrevealed parts...

Ion implantation induced structural changes in reactively sputtered Cr-N layers on Si substrates

International Nuclear Information System (INIS)

Novakovic, M.; Popovic, M.; Perusko, D.; Milinovic, V.; Radovic, I.; Bibic, N.; Mitric, M.; Milosavljevic, M.

2007-01-01

This paper presents a study of the structure and composition of reactively sputtered Cr-N layers as a function of deposition parameters, and the effects of ion implantation on these structures. The layers were deposited on (1 0 0) Si substrates to a thickness of 240-280 nm, at different nitrogen partial pressure, and subsequently irradiated with 120 keV Ar ions. Structural characterisation of the samples was performed with Rutherford backscattering spectroscopy, transmission electron microscopy and X-ray diffraction analysis. We also measured their electrical resistivity with a four point probe. It was found that the layers grow in form of columnar structures, and their composition, Cr 2 N or CrN, strongly depends on the nitrogen partial pressure during deposition. Ion irradiation induces local micro-structural changes, formation of nano-particles and defects, which can be nicely correlated to the measured electrical resistivity

Ciprofloxacin blocked enterohepatic circulation of diclofenac and alleviated NSAID-induced enteropathy in rats partly by inhibiting intestinal β-glucuronidase activity

Science.gov (United States)

Zhong, Ze-yu; Sun, Bin-bin; Shu, Nan; Xie, Qiu-shi; Tang, Xian-ge; Ling, Zhao-li; Wang, Fan; Zhao, Kai-jing; Xu, Ping; Zhang, Mian; Li, Ying; Chen, Yang; Liu, Li; Xia, Lun-zhu; Liu, Xiao-dong

2016-01-01

Aim: Diclofenac is a non-steroidal anti-inflammatory drug (NSAID), which may cause serious intestinal adverse reactions (enteropathy). In this study we investigated whether co-administration of ciprofloxacin affected the pharmacokinetics of diclofenac and diclofenac-induced enteropathy in rats. Methods: The pharmacokinetics of diclofenac was assessed in rats after receiving diclofenac (10 mg/kg, ig, or 5 mg/kg, iv), with or without ciprofloxacin (20 mg/kg, ig) co-administered. After receiving 6 oral doses or 15 intravenous doses of diclofenac, the rats were sacrificed, and small intestine was removed to examine diclofenac-induced enteropathy. β-Glucuronidase activity in intestinal content, bovine liver and E coli was evaluated. Results: Following oral or intravenous administration, the pharmacokinetic profile of diclofenac displayed typical enterohepatic circulation, and co-administration of ciprofloxacin abolished the enterohepatic circulation, resulted in significant reduction in the plasma content of diclofenac. In control rats, β-glucuronidase activity in small intestinal content was region-dependent: proximal intestinediclofenac, typical enteropathy was developed with severe enteropathy occurred in distal small intestine. Co-administration of ciprofloxacin significantly alleviated diclofenac-induced enteropathy. Conclusion: Co-administration of ciprofloxacin attenuated enterohepatic circulation of diclofenac and alleviated diclofenac-induced enteropathy in rats, partly via the inhibition of intestinal β-glucuronidase activity. PMID:27180979

Ciprofloxacin blocked enterohepatic circulation of diclofenac and alleviated NSAID-induced enteropathy in rats partly by inhibiting intestinal β-glucuronidase activity.

Science.gov (United States)

Zhong, Ze-Yu; Sun, Bin-Bin; Shu, Nan; Xie, Qiu-Shi; Tang, Xian-Ge; Ling, Zhao-Li; Wang, Fan; Zhao, Kai-Jing; Xu, Ping; Zhang, Mian; Li, Ying; Chen, Yang; Liu, Li; Xia, Lun-Zhu; Liu, Xiao-Dong

2016-07-01

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID), which may cause serious intestinal adverse reactions (enteropathy). In this study we investigated whether co-administration of ciprofloxacin affected the pharmacokinetics of diclofenac and diclofenac-induced enteropathy in rats. The pharmacokinetics of diclofenac was assessed in rats after receiving diclofenac (10 mg/kg, ig, or 5 mg/kg, iv), with or without ciprofloxacin (20 mg/kg, ig) co-administered. After receiving 6 oral doses or 15 intravenous doses of diclofenac, the rats were sacrificed, and small intestine was removed to examine diclofenac-induced enteropathy. β-Glucuronidase activity in intestinal content, bovine liver and E coli was evaluated. Following oral or intravenous administration, the pharmacokinetic profile of diclofenac displayed typical enterohepatic circulation, and co-administration of ciprofloxacin abolished the enterohepatic circulation, resulted in significant reduction in the plasma content of diclofenac. In control rats, β-glucuronidase activity in small intestinal content was region-dependent: proximal intestinediclofenac, typical enteropathy was developed with severe enteropathy occurred in distal small intestine. Co-administration of ciprofloxacin significantly alleviated diclofenac-induced enteropathy. Co-administration of ciprofloxacin attenuated enterohepatic circulation of diclofenac and alleviated diclofenac-induced enteropathy in rats, partly via the inhibition of intestinal β-glucuronidase activity.

Physical origin of the incubation time of self-induced GaN nanowires

International Nuclear Information System (INIS)

Consonni, V.; Trampert, A.; Geelhaar, L.; Riechert, H.

2011-01-01

The nucleation process of self-induced GaN nanowires grown by molecular beam epitaxy has been investigated by reflection high-energy electron diffraction measurements. It is found that stable nuclei in the form of spherical cap-shaped islands develop only after an incubation time that is strongly dependent upon the growth conditions. Its evolution with the growth temperature and gallium rate has been described within standard island nucleation theory, revealing a nucleation energy of 4.9 ± 0.1 eV and a very small nucleus critical size. The consideration of the incubation time is critical for the control of the nanowire morphology.

Brain levels of N-acylethanolamine phospholipids in mice during pentylenetetrazol-induced seizure

DEFF Research Database (Denmark)

Moesgaard, B.; Hansen, H.H.; Petersen, G.

2003-01-01

occur in response to seizure activity. Therefore, we investigated the effect of pentylenetetrazol (PTZ)-induced seizures in PTZ-kindled mice on the level of NAPE in the brain. Male NMRI mice were kindled with PTZ injections 3 times/wk, thereby developing clonic seizures in response to PTZ. Mice were...... killed within 30 min after the clonic seizure on the test day (12th injection) and the brains were collected. Eight species of NAPE were analyzed as the glycerophospho-N-acylethanolamines by high-performance liquid chromatography-coupled electrospray ionization mass spectrometry. No effect of the PTZ...... accumulate during seizure....

Pressure-induced magnetic transition in Fe sub 4 N probed by Fe K-edge XMCD measurement

CERN Document Server

Ishimatsu, N; Maruyama, H; Kawamura, N; Suzuki, M; Ohishi, Y; Ito, M; Nasu, S; Kawakami, T

2003-01-01

X-ray magnetic circular dichroism (XMCD) of gamma'-iron nitride (Fe sub 4 N) was recorded at Fe K-edge under high pressure up to 27 GPa. The XMCD intensity decreased remarkably with pressure, and vanished at 24 GPa. Compressibility was measured by the X-ray diffraction method. These results indicate that Fe sub 4 N undergoes a second-order phase transition from the ferromagnetic state to a paramagnetic state without any structural change. The pressure-induced demagnetizing process is discussed in terms of the Fe magnetic states in the local environment.

Assessing a sustainable sugar cane production system in Tucumán, Argentina: Part 2: Soil water and thermal regime, stalk population dynamics and sugarcane production Evaluación de un sistema sustentable de producción de caña de azúcar en Tucumán, R. Argentina: Parte II: Contenido de humedad y temperatura del suelo, dinámica de la población de tallos y producción de caña de azúcar

OpenAIRE

Patricia A. Digonzelli; M. Javier Tonatto; Eduardo R. Romero; G. Agustín Sanzano; Juan Fernández de Ullivarri; Juan A. Giardina; Jorge Scandaliaris

2011-01-01

The need to implement sustainable and productive systems compatible with populations leads to the elimination of burning as a practice associated with sugarcane harvesting. This work is part of a study where two sugarcane production systems were compared: a) with trash blanket (mulching) and b) without trash blanket (burnt residue). Macroplots were established in a commercial field planted with LCP 85-384, in Albarracín (Cruz Alta, Tucumán, Argentina). A split-plot experimental design with th...

Total and (n, 2n) neutron cross section measurements on 241Am

International Nuclear Information System (INIS)

Sage, C.

2009-01-01

Neutron induced reaction cross sections on 241 Am have been measured at the IRMM in Geel, Belgium, in the frame of a collaboration between the EC Joint Research Centres IRMM and ITU and French laboratories from CNRS and CEA. Raw material coming from the Atalante facility of CEA Marcoule has been transformed into suitable AmO 2 samples embedded in Al 2 O 3 and Y 2 O 3 matrices. The irradiations for the 241 Am(n, 2n) 240 Am reaction cross section measurement were carried out at the 7 MV Van de Graaff accelerator using the activation technique with quasi mono-energetic neutrons from 8 to 21 MeV produced via the D(d, n) 3 He and the T(d, n) 4 He reactions. The cross section was determined relative to the 27 Al(n, α) 24 Na standard cross section and was investigated for the first time above 15 MeV. The induced activity was measured off-line by standard γ-ray spectrometry using a high purity Ge detector. A special effort was made for the estimation of the uncertainties and the correlations between our experimental points. A different sample of the same isotope 241 Am has been measured in transmission and capture experiments in the resolved resonance region at the neutron ToF facility GELINA. The transmission measurement was performed in two campaigns, with an upgrade of the whole data acquisition system in between, followed by an investigation of its new performances. A preliminary analysis of the resonance parameters tends to confirm the recent evaluation to a higher value for the cross section at the bottom of the first resonances. A new design of C 6 D 6 detectors for capture measurements has been studied, but the data reduction and analysis of the measurement are not part of this work. (author) [fr

Exercise-induced dyspnea is a problem among the general adolescent population.

Science.gov (United States)

Johansson, H; Norlander, K; Hedenström, H; Janson, C; Nordang, L; Nordvall, L; Emtner, M

2014-06-01

Respiratory symptoms during exercise are common and might limit adolescents' ability to take part in physical activity. To estimate the prevalence, determinants and consequences of exercise-induced dyspnea (EID) on daily life in a general population of 12-13 year old adolescents. A letter was sent to the parents of all 12-13 year old adolescents in the city of Uppsala (n = 3838). Parents were asked to complete a questionnaire together with their child on EID, asthma and allergy, consequences for daily life (wheeze, day time- and nocturnal dyspnea) and physical activity. The response rate was 60% (n = 2309). Fourteen percent (n = 330) reported EID, i.e. had experienced an attack of shortness of breath that occurred after strenuous activity within the last 12 months. Female gender, ever-asthma and rhinitis were independently associated with an increased risk of EID. Ever-asthma was reported by 14.6% (n = 338), and 5.4% (n = 128) had both EID and ever-asthma. Sixty-one percent (n = 202) of the participants with EID did not have a diagnosis of asthma. In addition to rhinitis, participants with EID reported current wheeze and day-time as well as nocturnal dyspnea more often than the group without EID. No difference was found in the level of physical activity between participants with and without EID. Adolescents with undiagnosed exercise-induced dyspnea have respiratory symptoms and are affected in daily life but have the same level of physical activity as adolescents without exercise-induced respiratory symptoms. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influencia del tamaño de partícula, humedad y temperatura en el grado de gelatinización durante el proceso de extrusión de maca (Lepidium meyenii Walp)

OpenAIRE

Vílchez Túpac, Luz M.; Guevara Pérez, Américo; Encina Zelada, Christian R.

2012-01-01

Se trabajó con maca procedente de la meseta del Bombón - Junín, que al ser evaluada reportó el siguiente contenido químico-proximal (porcentaje en base seca): proteína 14,61, grasa 0,90, fibra 5,85, ceniza 4,97 y carbohidratos 79,53. Fueron 20 los tratamientos sometidos a extrusión, obteniendo mejores resultados al trabajar con un tamaño de partícula comprendido entre 0,17 a 0,20 cm, 12% de humedad, temperatura de inicio de extrusión 100°C, rotación del tornillo 254 r.p.m. (velocidad baja) y ...

Mapping sequences by parts

Directory of Open Access Journals (Sweden)

Guziolowski Carito

2007-09-01

Full Text Available Abstract Background: We present the N-map method, a pairwise and asymmetrical approach which allows us to compare sequences by taking into account evolutionary events that produce shuffled, reversed or repeated elements. Basically, the optimal N-map of a sequence s over a sequence t is the best way of partitioning the first sequence into N parts and placing them, possibly complementary reversed, over the second sequence in order to maximize the sum of their gapless alignment scores. Results: We introduce an algorithm computing an optimal N-map with time complexity O (|s| × |t| × N using O (|s| × |t| × N memory space. Among all the numbers of parts taken in a reasonable range, we select the value N for which the optimal N-map has the most significant score. To evaluate this significance, we study the empirical distributions of the scores of optimal N-maps and show that they can be approximated by normal distributions with a reasonable accuracy. We test the functionality of the approach over random sequences on which we apply artificial evolutionary events. Practical Application: The method is illustrated with four case studies of pairs of sequences involving non-standard evolutionary events.