Search Results - (Author, Cooperation:J. Mendez)

2018-01-13

Wiley-Blackwell

0148-0227

Geosciences

Physics

2018-03-06

Wiley-Blackwell

1085-3278

1099-145X

Geography

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

2018-06-16

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

2018-05-16

American Physical Society (APS)

0556-2813

1089-490X

Physics

Nuclear Structure

2018-10-26

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2012-09-29

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

2015-11-28

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2014-08-01

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Cell Aging/genetics/*physiology ; Cell Proliferation ; DNA Damage/genetics ; DNA Replication/*physiology ; DNA, Ribosomal/genetics ; Female ; Gene Expression Regulation ; Hematopoietic Stem Cells/cytology/*pathology ; Histones/genetics/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Minichromosome Maintenance Proteins/genetics ; *Stress, Physiological

1573-7438

Springer Online Journal Archives 1860-2000

Medicine

Résumé Des cas de trichinelloses chez des porcs en Bolivie ont été rapportés pour la première fois en 1993 après le suivi d'un petit abattoir d'une Communauté rurale de l'Altiplano bolivien. La présente étude s'intéressa à la présence d'anticorps contreTrichinella spiralis chez des porcs pour les 2 plus grands départements boliviens en terme de production porcine. L'étude de 3 abattoirs géographiquement distincts fut conduite pour couvrir les principales aires de production dans les Départements de Santa Cruz et de Chuqisaca. Les serums furent testés par ELISA. Parmi les 1327 serums analyses pour les 3 zones, 13,4% furent positifs. Les résultats de séropositivité pour les 3 zones varient entre 10,2% et 17,1%. Cependant, pour les 3 zones étudiées des variations trés significatives de séropositivité furent observées avec des pourcentages de séropositivité les plus élévés pour les zones ayant des systèmes de production extensive. De telles variations sont probablement dùes aux différences de nutrition par fourrage et déchets ménagés, principales composantes du régime alimentaire des porcs dans les systèmes de production extensive. Les résultats de cette étude furent similaires à ceux obtenus lors d'une étude précédente dans l'Altiplano, indiquant que la trichinellose est présente dans toute la Bolivie et apparait potentiellement comme un problème important de santè publique.

Resumen La triquinosis porcina fue detectada por primera vez en Bolivia en 1993 después de un estudio realizado en un matadero situado en una pequeña comunidad del altiplano. En est artículo se investigó la presencia de anticuerpos frente aTrichinella spiralis en cerdos en los 2 departamentos con una mayor cabaña porcina de Bolivia. Se estudiaron 3 matederos separados entre sí con objeto de cubrir las principales áreas productoras de cerdos en los departamentos de Santa Cruz y Chuquisaca. Se realizaron tests ELISA para detectar anticuerpos en el suero. De las 1327 muestras analizadas en total, el 13·4% fueron positivas. Los resultados obtenidos en cada matadero variaron entre el 10·2 y el 17·1% de seropositivos. No obstante, dentro de cada matadero se encontró una gran variabilidad, y aquellas áreas con sistemas de producción más extensivos fueron las que tuvieron porcentajes más altos de animales positivos. Esto se debe probablemente a diferencias en la alimentación, puesto que el pastoreo y el aprovechamiento de residuos domésticos son más importantes en los sistemas extensivos. Estos resultados son similares a los obtenidos anteriormente en otros estudios realizados en el altiplano e indican que la triquinosis está extendida en Bolivia y supone un peligro potencial para la salud humana.

Summary Trichinellosis in pigs in Bolivia was first documented in 1993 following a small abattoir survey in a rural community in the Bolivian Altiplano. The present study investigated the presence of antibodies toTrichinella spiralis in pigs in the 2 largest departments in terms of pig production in Bolivia. Three geographically separate abattoir surveys were conducted to cover the major production areas in the Departments of Santa Cruz and Chuquisaca. Sera were tested using an enzymelinked immunosorbent assay. Of the 1,327 sera analysed from the 3 areas, 13·4% overall tested positive. Results from the 3 individual surveys varied from 10·2% seropositivity to 17·1 per cent. However, within each of the 3 sample areas, highly significant variation in seropositivity was encountered, with those areas with the most extensive production systems having the highest percentage of positive sera. Such variation is probably due to differences in nutrition with foraging and household waste being important components of pig diets in extensive production systems. The results of this study were similar to those obtained from the previous survey in the Altiplano and indicate that trichinellosis is present throughout Bolivia and is a potentially important public health problem.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p〈0.05). Plasma viremia was closely associated (p〈0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of 〉500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p〈0.05).

Electronic Resource

2018-12-17

Italian Society of Silviculture and Forest Ecology

1971-7458

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

An absolute reflectometer is described, which can determine the optical constants of thin films prepared and maintained in ultrahigh vacuum (UHV) in the 30–200 nm far-ultraviolet (FUV) region. The optical constants are calculated with Fresnel equations from reflectance measurements as a function of the incidence angle, which can be continuously varied from near-normal to grazing incidence. Corrections for the surface roughness effects of both the deposited film and the substrate on the reflectance in the calculation of optical constants were incorporated. The surface roughness was determined by atomic force microscopy. An innovative feature of the instrument is an oxidation chamber containing an atomic oxygen source attached to the reflectometer. Inside this chamber the FUV reflectance degradation of materials, caused by oxidation processes in low earth orbits, can be simulated on freshly prepared UHV samples. Another improvement of the reflectometer is the capability of performing the reflectance measurements in two perpendicular incidence planes. The average of these measurements obviates the unknown of the polarization state of the light beam emerging from the monochromator. However, this averaging may become inexact in the presence of a lateral inversion error in the reflected beam caused by the lack of uniformity of the beam and the detector.A modification in the calculation algorithm was introduced to reduce the influence of this error. The implementation of a differential pressure system in four stages and a specifically designed device for modulation and monitoring of the light beam has allowed the use of weak spectral lines and the continuum of helium from the emission of a windowless capillary discharge lamp. Some results of reflectance measurements on freshly prepared aluminum films and after exposure to controlled doses of atomic oxygen are presented. © 1996 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

A pulsed excimer laser was used to evaporate targets of boron nitride and titanium nitride in an attempt to produce hard thin films on crystalline silicon substrates. The films were either pure TiN or BN layers, as well as alternating multilayers and mixed layers. Deposition could be assisted by ion bombardment. The films were characterized by Auger electron spectroscopy, Fourier transform infrared spectroscopy (FTIR), and x-ray diffraction. A selection of films was also studied by profilometry in order to determine deposition rate and the type of stress present. The level of stress in TiN films was also a function of the deposition temperature and could be varied with the use of ion bombardment. Amorphous, cubic, and hexagonal BN films were produced and the effect of the stress of the substrate on these layers was investigated. Multilayers were stressed, having alternating layers of nanocrystalline TiN and amorphous BN. Mixtures consisted of nanometer-sized regions of crystalline TiN and sp2 coordinated boron nitride. FTIR spectra and high-resolution transmission electron microscope pictures suggested that in the mixtures, boron nitride planes tended to parallel the surface of the TiN grains. No sign of stress-driven formation of cubic BN was observed in the multilayers nor in the nanosized mixtures, regardless of the stress level present in them; neither was there any sign of titanium borides or other structures that might increase the hardness of the films. © 2000 American Institute of Physics.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Ionotropic glutamate receptors in cerebellar Bergmann glial cells are linked to transcriptional regulation and, by these means, are thought to play an important role in plasticity, learning and memory and in several neuropathologies. Within the CNS, the transcription factors of the POU family bind their target DNA sequences after a growth factor-dependent phosphorylation–dephosphorylation cascade. Exposure of cultured Bergmann glial cells to glutamate leads to a time- and dose-dependent increase in Oct-2 DNA-binding activity. The use of specific pharmacological tools established the involvement of Ca2+-permeable α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors. Furthermore, the signaling cascade includes phosphatidyl inositol 3-kinase as well as protein kinase C activation. Interestingly, transcriptional as well as translational inhibitors abolish the glutamate effect, suggesting a transcriptional up-regulation of the oct-2 gene. These data demonstrate that Oct-2 expression is not restricted to neurons and further strengthen the notion that the glial glutamate receptors participate in the modulation of glutamatergic cerebellar neurotransmission.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

High temperature structural changes in a W wire are studied in situ by scanning electron microscopy. This is made possible by the microscopic size of the wire. Grain-boundary grooving and faceting are observed in real time. The constriction exhibits a strong thermal gradient (∼100 K μm−1) which is the driving force for the migration mechanisms responsible for the observed phenomena.

Electronic Resource

1574-6968

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The interaction of Entamoeba histolytica trophozoites with collagen type I and calcium induces a membrane to nuclei signaling. The transduction pathways involved in such phenomena are still poorly understood. Using a combination of immunoprecipitation assays, Western immunoblot analysis, electrophoretic mobility shift assays and immunocytochemistry we demonstrate here the expression, tyrosine phosphorylation, nuclear translocation and DNA binding of two members of the signal transducers and activators of transcription family of inducible transcription factors in the protozoan parasite E. histolytica. These results support the notion that the interaction of the extracellular matrix components with the parasite turns on a genetic program that facilitates the invasion of the host.

Electronic Resource

1365-2516

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1750-3841

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Process Engineering, Biotechnology, Nutrition Technology

SUMMARY— p-Hydroxybenzoic, ferulic and vanillic acids were isolated from hydrolyzed and non-hydrolyzed extracts of seeds of Pisum sativum L. var. Feltham and var. Lincoln. In the Feltham variety syringic acid was only present as the free compound but p-coumaric acid occurred in both the free and bound forms. Indole-3-acetic and, tentatively, indole-3-carboxylic acids were identified in the Lincoln variety. It is very doubtful if phenols present in the minimal concentration found could play any role in the edible characteristics of the peas.

Electronic Resource

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource