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1.
Nanotechnology ; 25(50): 505301, 2014 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-25427225

RESUMEN

In order to realize a versatile high throughput production of micro-optical elements, UV-curable polymer composites containing titanium dioxide nanoparticles were prepared and characterized. The composites are based on an industrial prototype epoxy polymer. Titanium dioxide nanoparticles smaller than 10 nm were synthesized by the nonaqueous sol method and in situ sterically stabilized by three different organic surfactants. The composites exhibit high transparency. Distinct alteration of optical transmission properties for visible light and near IR wavelength range could be avoided by adaption of the stabilizing organic surfactant. Most importantly, the refractive index (RI) of the composites that depends on the fraction of incorporated inorganic nanoparticles could be directly tuned. E.g. the RI at a wavelength of 635 nm of a composite containing 23 wt% titanium dioxide nanoparticles is increased to 1.626, with respect to a value of 1.542 for the pure polymer. Furthermore, it could be demonstrated that the prepared inorganic-organic nanocomposites are well suited for the direct fabrication of low-cost micro-optical elements by nanoimprint lithography. A low response of the optical composite properties to temperature treatment up to 220 °C with a shrinkage of only about 4% ensures its application for integrated micro-optical elements in industrial production.

2.
Plant Dis ; 93(6): 625-631, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30764401

RESUMEN

In a 2-year study, the temporal development of Cercospora leaf spot (Cercospora depazeoides) and berry yield were evaluated in two production systems (integrated and organic) and in two winter pruning treatments (trees pruned to four and eight scaffolds) in two black elderberry (Sambucus nigra) orchards in Hungary. Under organic production, leaf spot onset occurred 2 to 4 weeks earlier (mid- and late July) in both years and both orchards compared with the integrated program. Disease then continuously progressed until the final assessment date (late September) in both years, reaching a maximum final disease incidence of 15.9% in the integrated system and of 38.2% in the organic system. In general, disease progress after late August was greater on trees pruned to eight scaffolds than on trees pruned to four scaffolds in both production systems. Both final disease incidence and area under the disease progress curves (AUDPC) were significantly lower (P < 0.001) in the integrated treatments compared with organic ones. Across all treatments, both disease measures were significantly (P < 0.05) lower on trees pruned to four scaffolds compared with trees pruned to eight scaffolds. However, when the effect of pruning on final disease incidence and AUDPC was analyzed separately for integrated and organic systems, pruning caused uniformly significant differences in disease development only for the organic system. Berry yield was significantly higher (P < 0.05) in the integrated system compared with the organic system, but pruning showed no significant effect on yield. Overall, pruning to four scaffolds resulted in consistently lower disease development in organic production compared to integrated. Thus, winter pruning may be useful as a Cercospora leaf spot management practice in organic elderberry orchards.

3.
Rev. Hosp. Clin. Univ. Chile ; 19(3): 239-244, 2008. tab, ilus
Artículo en Español | LILACS | ID: lil-530342

RESUMEN

High grade gliomas are lethal cancers. Despite recent advances in surgery, radiotherapy and chemotherapy, the overall survival is 15 months for glioblastoma. They are among the most vascular of human tumors, making them especially attractive targets for angiogenesis inhibitors. Most clinical trials of these agents as monotherapy have failed to demonstrate survival benefit in unselected high grade glioma patient populations. Several mechanisms of treatment failure have been postulated. In response, there are new intervention strategies on course: the combination of target therapy with classic chemotherapy, multitargeted kinase inhibitors and combinations of single-targeted kinase inhibitors and the identification of correlative biomarkers. These advances provide real opportunities for the development of effective therapies for high grade gliomas.


Asunto(s)
Humanos , Masculino , Femenino , Glioma/clasificación , Glioma/terapia , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/uso terapéutico , Astrocitoma , Neoplasias Encefálicas
4.
Artículo en Inglés | MEDLINE | ID: mdl-16568946

RESUMEN

Epigenetic mechanisms control eukaryotic development beyond DNA-stored information. DNA methylation, histone modifications and variants, nucleosome remodeling and noncoding RNAs all contribute to the dynamic make-up of chromatin under distinct developmental options. In particular, the great diversity of covalent histone tail modifications has been proposed to be ideally suited for imparting epigenetic information. While most of the histone tail modifications represent transient marks at transcriptionally permissive chromatin, some modifications appear more robust at silent chromatin regions, where they index repressive epigenetic states with functions also outside transcriptional regulation. Under-representation of repressive histone marks could be indicative of epigenetic plasticity in stem, young and tumor cells, while committed and senescent (old) cells often display increased levels of these more stable modifications. Here, we discuss profiles of normal and aberrant histone lysine methylation patterns, as they occur during the transition of an embryonic to a differentiated cell or in controlled self-renewal vs pro-neoplastic or metastatic conditions. Elucidating these histone modification patterns promises to have important implications for novel advances in stem cell research, nuclear reprogramming and cancer, and may offer novel targets for the combat of tumor cells, potentially leading to new diagnostic and therapeutic avenues in human biology and disease.


Asunto(s)
Cromatina/genética , Cromatina/metabolismo , Epigénesis Genética/genética , Histonas/genética , Histonas/metabolismo , Animales , Diferenciación Celular/genética , Linaje de la Célula/genética , Transformación Celular Neoplásica/genética , Desarrollo Embrionario/genética , Humanos , Metilación , Estructura Terciaria de Proteína/fisiología
5.
Allergy ; 59(2): 164-7, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14763929

RESUMEN

BACKGROUND: As the literature has only controversial data on the role of nonallergen-specific antibodies in atopic eczema dermatitis syndrome, the authors investigated the link between the occurrence of the antiphospholipid [anticardiolipin (ACL), anti-beta2-glycoprotein I] and allergen-specific immunoglobulin E (IgE) antibodies in 72 children with atopic eczema/dermatitis syndrome (AEDS). METHODS: The measurement of antiphospholipid antibodies was carried out by enzyme-linked immunosorbent assay (ELISA), serum total IgE by nephelometry, and allergen-specific IgE by immunoblotting assay. The statistical analysis was carried out by Fisher's exact test and odds ratio was calculated. RESULTS: Thirteen of 72 children with AEDS (mean age 8.3 years) had elevated serum levels of ACL, and eight anti-beta2-glycoprotein I antibodies. The presence of allergen-specific IgE against inhalant allergens and nutritive allergens was among eight of 13 and three of eight in the cases with elevated ACL. The ratio of patients with highly increased severity scoring of atopic dermatitis (SCORAD) index (>75) was significantly higher in the group with elevated (4/13) than in those with the normal ACL levels (2/59). There was a significant association between the appearance of mite (Dermatophagoides pteronyssinus, D. farinae)-specific IgE and ACL IgM antibodies (6/13). CONCLUSION: These findings show that there are significant linkage and association between the appearance of ACL IgM or the production of allergen-specific IgE against inhalant (mainly mite) allergens in children with atopic eczema/dermatitis syndrome.


Asunto(s)
Anticuerpos Anticardiolipina/sangre , Anticuerpos/sangre , Especificidad de Anticuerpos , Antígenos Dermatofagoides/inmunología , Dermatitis Atópica/inmunología , Inmunoglobulina E/sangre , Inmunoglobulina M/sangre , Adolescente , Alérgenos/inmunología , Autoanticuerpos/sangre , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Femenino , Glicoproteínas/inmunología , Humanos , Masculino , beta 2 Glicoproteína I
6.
Santiago de Chile; Gráfica Funny; 2004. 234 p. ilus, tab, graf.
Monografía en Español | MINSALCHILE | ID: biblio-1545434
7.
Appl Environ Microbiol ; 67(6): 2476-83, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11375153

RESUMEN

A random transposon-based mutagenesis system was optimized for the purple sulfur phototrophic bacterium Thiocapsa roseopersicina BBS. Screening for hydrogenase-deficient phenotypes resulted in the isolation of six independent mutants in a mini-Tn5 library. One of the mutations was in a gene showing high amino acid sequence similarity to HypF proteins in other organisms. Inactivation of hydrogen uptake activity in the hypF-deficient mutant resulted in a dramatic increase in the hydrogen evolution capacity of T. roseopersicina under nitrogen-fixing conditions. This mutant is therefore a promising candidate for use in practical biohydrogen-producing systems. The reconstructed hypF gene was able to complement the hypF-deficient mutant of T. roseopersicina BBS. Heterologous complementation experiments, using hypF mutant strains of T. roseopersicina, Escherichia coli, and Ralstonia eutropha and various hypF genes, were performed. They were successful in all of the cases tested, although for E. coli, the regulatory region of the foreign gene had to be replaced in order to achieve partial complementation. RT-PCR data suggested that HypF has no effect on the transcriptional regulation of the structural genes of hydrogenases in this organism.


Asunto(s)
Proteínas Bacterianas/genética , Hidrogenasas/metabolismo , Procesamiento Proteico-Postraduccional , Proteobacteria/metabolismo , Thiocapsa roseopersicina/genética , Alphaproteobacteria/genética , Alphaproteobacteria/metabolismo , Betaproteobacteria/genética , Betaproteobacteria/metabolismo , Gammaproteobacteria/genética , Gammaproteobacteria/metabolismo , Prueba de Complementación Genética , Datos de Secuencia Molecular , Mutagénesis Insercional , Proteobacteria/genética , Análisis de Secuencia de ADN , Thiocapsa roseopersicina/enzimología , Transcripción Genética
8.
Pflugers Arch ; 439(3 Suppl): R81-3, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10653150

RESUMEN

A fundamental and principal difficulty of the future energy supply is that the formation of fossil fuels is much slower than the rate of their exploitation. Therefore the reserves which can be recovered in an energetically feasible manner are shrinking parallel with an increasing world-wide energy demand. Among the alternative energy carriers, hydrogen is preferred because it is easy to transport and store and it burns to environmentally friendly water vapour when utilized. Hydrogen can be produced in biological systems, however, our understanding of the molecular details is just emerging.


Asunto(s)
Biotecnología/tendencias , Hidrógeno , Hidrogenasas , Metano/metabolismo , Nitrocompuestos/metabolismo
9.
Pflugers Arch ; 439(Suppl 1): r081-r083, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28176081

RESUMEN

A fundamental and principal difficulty of the future energy supply is that the formation of fossil fuels is much slower than the rate of their exploitation. Therefore the reserves which can be recovered in an energetically feasible manner are shrinking parallel with an increasing world-wide energy demand. Among the alternative energy carriers, hydrogen is preferred because it is easy to transport and store and it burns to environmentally friendly water vapour when utilized. Hydrogen can be produced in biological systems, however, our understanding of the molecular details is just emerging.

10.
FEMS Microbiol Lett ; 180(2): 317-24, 1999 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-10556728

RESUMEN

The dsr genes and the hydSL operon are present as separate entities in phototrophic sulfur oxidizers of the genera Allochromatium, Marichromatium, Thiocapsa and Thiocystis and are organized similarly as in Allochromatium vinosum and Thiocapsa roseopersicina, respectively. The dsrA gene, encoding the alpha subunit of 'reverse' siroheme sulfite reductase, is also present in two species of green sulfur bacteria pointing to an important and universal role of this enzyme and probably other proteins encoded in the dsr locus in the oxidation of stored sulfur by phototrophic bacteria. The hupSL genes are uniformly present in the members of the Chromatiaceae family tested. The two genes between hydS and hydL encode a membrane-bound b-type cytochrome and a soluble iron-sulfur protein, respectively, resembling subunits of heterodisulfide reductase from methanogenic archaea. These genes are similar but not identical to dsrM and dsrK, indicating that the derived proteins have distinct functions, the former in hydrogen metabolism and the latter in oxidative sulfur metabolism.


Asunto(s)
Bacterias/genética , Chlorobi/genética , Genes Bacterianos , Hidrógeno/metabolismo , Azufre/metabolismo , Bacterias/enzimología , Southern Blotting , Chlorobi/enzimología , Hidrogenasas/genética , Hidrogenasas/metabolismo , Oxidación-Reducción , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/genética , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/metabolismo , Filogenia
11.
Rev. méd. Chile ; 126(2): 199-201, feb. 1998.
Artículo en Español | LILACS | ID: lil-210564

RESUMEN

Primary malignant lymphomas of the bladder are infrequent. We report a 70 years old woman presenting with hematurla, dysuria, malaise and a 5 Kg weigbt loss. Pelvic ultrasound examination showed a 8x8x8 cm solid and cystic mass adjacent to the bladder and uterus. Cytoscopic biopsy disclosed a low grade B cell non Hodgkin lymphoma. She was treated with 6 cycles of chemotherapy with disappearance of the mass. Two years after admission, the patient is free of disease


Asunto(s)
Humanos , Femenino , Anciano , Neoplasias de la Vejiga Urinaria/diagnóstico , Linfoma de Células B de la Zona Marginal/diagnóstico , Neoplasias de la Vejiga Urinaria/terapia , Linfoma de Células B de la Zona Marginal/terapia , Hematuria/etiología
12.
Rev. méd. Chile ; 123(1): 51-60, ene. 1995. tab
Artículo en Español | LILACS | ID: lil-151159

RESUMEN

Aiming to assess the association between carotenes and vitamin A intake and lung cancer, a case control study was performed. Sixty one male subjects with lung cancer and 61 controls paired for age, sex and smoking habits from 6 hospitals in Santiago were analyzed. Based on a compsumption tendency enquiry, the mean weekly intake of food showed that cases consumed less winter vegetables than controls (chard, beet, chicory, spinach and cabbage) but no differences between groups in carotene and retinol consumption. It is concluded that patients with lung cancer have a lower consumption of carotene rich vegetables


Asunto(s)
Humanos , Masculino , Carotenoides/deficiencia , Neoplasias Pulmonares/etiología , Conducta Alimentaria , Vitamina A , Vitaminas en la Dieta/análisis , Fumar/efectos adversos , Estudios de Casos y Controles , Encuestas sobre Dietas , Factores de Riesgo , Exposición a Riesgos Ambientales/efectos adversos , Factores Socioeconómicos
14.
Orv Hetil ; 135(29): 1595-7, 1994 Jul 17.
Artículo en Húngaro | MEDLINE | ID: mdl-8058304

RESUMEN

Transition of a (probably primary) cutaneous non-Hodgkin's lymphoma to T-stem cell leukaemia was observed in a case. Unusual clinical features, histological and laboratory data hampered the diagnosis-making of this rare disease. Using the ALL-BFM 90 HRG protocoll complete remission was achieved. Under the treatment varicella-zoster virus encephalitis took place.


Asunto(s)
Leucemia-Linfoma de Células T del Adulto/complicaciones , Linfoma Cutáneo de Células T/complicaciones , Neoplasias Cutáneas/complicaciones , Niño , Protocolos Clínicos , Femenino , Humanos , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , Leucemia-Linfoma de Células T del Adulto/patología , Linfoma Cutáneo de Células T/tratamiento farmacológico , Linfoma Cutáneo de Células T/patología , Neoplasias Primarias Múltiples/tratamiento farmacológico , Neoplasias Primarias Múltiples/patología , Inducción de Remisión , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Síndrome
16.
Rev. Inst. Nac. Cancerol. (Méx.) ; 38(2): 1555-63, abr.-jun. 1992.
Artículo en Español | LILACS | ID: lil-118245

RESUMEN

El presente artículo analiza la eventual evolución de un paciente con cáncer desde el punto de vista de los factores psicológicos involucrados. El trabajo se expone en tres secciones: I Factores de riesgo, II Aparición de la enfermedad y III Fase terminal. Entre los factores de riesgo psicológico se revisan variables de personalidad, experiencias de duelo o de pérdida, rol de la depresión y su concatenación con cambios endócrinos e inmunológicos, presentando dos casos clínicos como ejemplo. Respecto a la aparición de la enfermedad se discuten aspectos sobre la información del diagnóstico a los pacientes y sus familias, concluyéndose que dentro de determinadas circunstancias es preferible proporcionar la información veraz del diagnóstico al paciente y a la familia. La situación del paciente terminal se ilustra con un fragmento de la novela La muerte de Iván Ilich de León Tolstoi. Se comentan situaciones de angustia y depresión en estos enfermos, así como mecanismos de defensa como el desplazamiento y la intensificación de los rasgos de personalidad. El trabajo considera también el impacto que tiene el manejo de este tipo de enfermos sobre el médico y el equipo de salud, así como los mecanismos de defensa a los que recurren estos profesionales. Se concluye que el hilo conductor de todas las etapas por las cuales atraviesa el paciente con cáncer son las relaciones interpersonales. Y dado que la atención de estos enfermos es intrahospitalaria en gran parte de su evolución, el médico y el personal de salud tienen un papel fundamental en el manejo de los aspectos psicológicos.


Asunto(s)
Humanos , Femenino , Adulto , Persona de Mediana Edad , Neoplasias/psicología , Trastornos Psicofisiológicos/psicología , Adaptación Psicológica , Chile , Factores de Riesgo
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