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1.
Poult Sci ; 103(2): 103315, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38159421

RESUMEN

A chick assay was conducted to determine the effects of Zn source on performance and to establish a Zn relative bioavailability value (RBV) for a new source of Zn hydroxychloride. In the assay, 8-day-old chicks were fed a Zn-deficient soy protein concentrate diet supplemented with 0, 7, and 15 mg Zn/kg from feed grade ZnSO4 monohydrate for 14 d to establish a standard response curve. The same basal diet was supplemented with 3, 7, and 10 mg Zn/kg from a new Zn hydroxychloride (SAMZn). A second source of Zn hydroxychloride (IBZn) was supplemented at 10 mg Zn/kg as a direct comparison to the highest level of SAMZn. Weight gain increased (P < 0.05) with increasing Zn level, regardless of source. Weight gain of chicks fed 7 mg Zn/kg from SAMZn was not different (P > 0.05) from chicks fed 15 mg Zn/kg from ZnSO4. Weight gain was not different (P > 0.05) when comparing the 2 sources of Zn hydroxychloride supplemented at 10 mg Zn/kg. Tibia ash Zn and total tibia Zn were increased (P < 0.05) by all Zn sources and responded linearly (P < 0.05) to Zn supplementation from ZnSO4 and SAMZn. Total tibia Zn concentration was not different (P > 0.05) for chicks fed 10 mg Zn/kg from either source of Zn hydroxychloride. Multiple linear regression of total tibia Zn on supplemental Zn intake (R2 = 0.95) resulted in a RBV of 115% for SAMZn compared with ZnSO4 (set at 100%). The RBV of SAMZn was higher (P < 0.05) than ZnSO4. In conclusion, relative bioavailability of Zn (based on tibia Zn) in Zn hydroxychloride from SAMZn was higher than feed grade ZnSO4 based on multiple regression slope-ratio analysis and was similar to that of IBZn Zn hydroxychloride based on tibia Zn responses to 10 mg/kg supplemental dietary Zn.


Asunto(s)
Pollos , Zinc , Animales , Zinc/metabolismo , Disponibilidad Biológica , Pollos/metabolismo , Sulfato de Zinc/metabolismo , Suplementos Dietéticos , Dieta/veterinaria , Aumento de Peso , Alimentación Animal
2.
Rep Prog Phys ; 85(12)2022 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-36279854

RESUMEN

The interpretation of pulsar rotational glitches, the sudden increase in spin frequency of neutron stars, is a half-century-old challenge. The common view is that glitches are driven by the dynamics of the stellar interior, and connect in particular to the interactions between a large-scale neutron superfluid and the other stellar components. This thesis is corroborated by observational data of glitches and the post-glitch response seen in pulsars' rotation, which often involves very long timescales, from months to years. As such, glitch observables combined with consistent models incorporating the rich physics of neutron stars-from the lattice structure of their crust to the equation of state for matter beyond nuclear densities-can be very powerful at placing limits on, and reduce uncertainties of, the internal properties. This review summarises glitch observations, current data, and recent analyses, and connects them to the underlying mechanisms and microphysical parameters in the context of the most advanced theoretical glitch models to date.

3.
Mon Not R Astron Soc ; 498(3): 4396-4403, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33204043

RESUMEN

PSR J1813-1749 is one of the most energetic rotation-powered pulsars known, producing a pulsar wind nebula (PWN) and gamma-ray and TeV emission, but whose spin period is only measurable in X-ray. We present analysis of two Chandra datasets that are separated by more than ten years and recent NICER data. The long baseline of the Chandra data allows us to derive a pulsar proper motion µ R.A. = - ( 0 . ″ 067 ± 0 . ″ 010 ) yr-1 and µ decl. = - ( 0 . ″ 014 ± 0 . ″ 007 ) yr-1 and velocity v ⊥ ≈ 900-1600 km s-1 (assuming a distance d = 3 - 5 kpc), although we cannot exclude a contribution to the change in measured pulsar position due to a change in brightness structure of the PWN very near the pulsar. We model the PWN and pulsar spectra using an absorbed power law and obtain best-fit absorption N H = (13.1 ± 0.9) × 1022 cm-2, photon index Γ = 1.5 ± 0.1, and 0.3-10 keV luminosity L X ≈ 5.4 × 1034 erg s-1(d/ 5 kpc)2 for the PWN and Γ = 1.2 ± 0.1 and L X « 9.3 × 1033 erg s-1(d/ 5 kpc)2 for PSR J1813-1749. These values do not change between the 2006 and 2016 observations. We use NICER observations from 2019 to obtain a timing model of PSR J1813-1749, with spin frequency ν = 22.35 Hz and spin frequency time derivative v . = ( - 6.428 ± 0.003 ) × 10 - 11 Hz s-1. We also fit ν measurements from 2009-2012 and our 2019 value and find a long-term spin-down rate v . = ( - 6.3445 ± 0.0004 ) × 10 - 11 Hz s-1. We speculate that the difference in spin-down rates is due to glitch activity or emission mode switching.

4.
Mon Not R Astron Soc ; 498(4): 4605-4614, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33149372

RESUMEN

PSR J0537-6910, also known as the Big Glitcher, is the most prolific glitching pulsar known, and its spin-induced pulsations are only detectable in X-ray. We present results from analysis of 2.7 years of NICER timing observations, from 2017 August to 2020 April. We obtain a rotation phase-connected timing model for the entire timespan, which overlaps with the third observing run of LIGO/Virgo, thus enabling the most sensitive gravitational wave searches of this potentially strong gravitational wave-emitting pulsar. We find that the short-term braking index between glitches decreases towards a value of 7 or lower at longer times since the preceding glitch. By combining NICER and RXTE data, we measure a long-term braking index n = -1.25 ± 0.01. Our analysis reveals 8 new glitches, the first detected since 2011, near the end of RXTE, with a total NICER and RXTE glitch activity of 8.88 × 10-7 yr-1. The new glitches follow the seemingly unique time-to-next-glitch-glitch-size correlation established previously using RXTE data, with a slope of 5 d µHz-1. For one glitch around which NICER observes two days on either side, we search for but do not see clear evidence of spectral nor pulse profile changes that may be associated with the glitch.

5.
Sci Adv ; 1(9): e1500578, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26601293

RESUMEN

Pulsars are known for their superb timing precision, although glitches can interrupt the regular timing behavior when the stars are young. These glitches are thought to be caused by interactions between normal and superfluid matter in the crust of the star. However, glitching pulsars such as Vela have been shown to require a superfluid reservoir that greatly exceeds that available in the crust. We examine a model in which glitches tap the superfluid in the core. We test a variety of theoretical superfluid models against the most recent glitch data and find that only one model can successfully explain up to 45 years of observational data. We develop a new technique for combining radio and x-ray data to measure pulsar masses, thereby demonstrating how current and future telescopes can probe fundamental physics such as superfluidity near nuclear saturation.

6.
BMC Microbiol ; 15: 187, 2015 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-26410025

RESUMEN

BACKGROUND: Antimicrobial photodynamic therapy has been proposed as an alternative to suppress subgingival species. This results from the balance among Streptococcus sanguis, Streptococcus mutans and Candida albicans in the dental biofilm. Not all the photosensitizers have the same photodynamic effect against the different microorganims. The objective of this study is to compare in vitro the photodynamic effect of methylene blue (MB), rose Bengal (RB) and curcumin (CUR) in combination with white light on the cariogenic microorganism S. mutans, S. sanguis and C. albicans. RESULTS: Photodynamic therapy with MB, RB and CUR inhibited 6 log 10 the growth of both bacteria but at different concentrations: 0.31-0.62 µg/ml and 0.62-1.25 µg/ml RB were needed to photoinactivate S. mutans and S. sanguis, respectively; 1.25-2.5 µg/ml MB for both species; whereas higher CUR concentrations (80-160 µg/ml and 160-320 µg/ml) were required to obtain the same reduction in S. mutans and S. sanguis viability respectively. The minimal fungicidal concentration of MB for 5 log10 CFU reduction (4.5 McFarland) was 80-160 µg/ml, whereas for RB it ranged between 320 and 640 µg/ml. For CUR, even the maximum studied concentration (1280 µg/ml) did not reach that inhibition. Incubation time had no effect in all experiments. CONCLUSIONS: Photodynamic therapy with RB, MB and CUR and white light is effective in killing S. mutans and S. sanguis strains, although MB and RB are more efficient than CUR. C. albicans required higher concentrations of all photosensitizers to obtain a fungicidal effect, being MB the most efficient and CUR ineffective.


Asunto(s)
Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Caries Dental/microbiología , Fármacos Fotosensibilizantes/farmacología , Candida albicans/efectos de los fármacos , Curcumina/farmacología , Caries Dental/tratamiento farmacológico , Técnicas In Vitro , Azul de Metileno/farmacología , Fotoquimioterapia , Rosa Bengala/farmacología , Streptococcus mutans/efectos de los fármacos , Streptococcus sanguis/efectos de los fármacos
7.
Mycoses ; 57(1): 35-42, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23905682

RESUMEN

Antimicrobial photodynamic therapy (aPDT) is an emerging alternative to treat infections based on the use of photosensitisers (PSs) and visible light. To investigate the fungicidal effect of PDT against azole-resistant Candida albicans strains using two PSs with a different mechanism of action, hypericin (HYP) and 1,9-dimethyl methylene blue (DMMB), comparing their efficacy and the reactive oxygen species (ROS) species involved in their cytotoxicity. Azole-resistant and the azole-susceptible C. albicans strains were used. Solutions of 0.5 and 4 McFarland inoculum of each Candida strain were treated with different concentrations of each PS, and exposed to two light-emitting diode light fluences (18 and 37 J cm⁻²). Mechanistic insight was gained using several ROS quenchers. The minimal fungicidal concentration of HYP for ≥3 log10 CFU reduction (0.5 McFarland) was 0.62 µmol l⁻¹ for most strains, whereas for DMMB it ranged between 1.25 and 2.5 µmol l⁻¹. Increasing the fluence to 37 J cm⁻² allowed to reduce the DMMB concentration. Higher concentrations of both PSs were required to reach a 6 log10 reduction (4 McFarland). H2O2 was the main phototoxic species involved in the fungicidal effect of HYP-aPDT whereas ¹O2 was more important for DMMB-based treatments. aPDT with either HYP or DMMB is effective in killing of C. albicans strains independent of their azole resistance pattern. HYP was more efficient at low fungal concentration and DMMB at higher concentrations.


Asunto(s)
Antifúngicos/farmacología , Azoles/farmacología , Candida albicans/efectos de los fármacos , Candida albicans/efectos de la radiación , Farmacorresistencia Fúngica , Azul de Metileno/análogos & derivados , Perileno/análogos & derivados , Fármacos Fotosensibilizantes/farmacología , Antracenos , Candida albicans/crecimiento & desarrollo , Candidiasis/tratamiento farmacológico , Candidiasis/microbiología , Terapia Combinada , Humanos , Luz , Azul de Metileno/farmacología , Pruebas de Sensibilidad Microbiana , Perileno/farmacología , Fotoquimioterapia
8.
Paediatr Int Child Health ; 33(4): 259-72, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24196701

RESUMEN

BACKGROUND: Armed conflict has broad-ranging impacts on the mental health and wellbeing of children and adolescents. Mental health needs greatly exceed service provision in conflict settings, particularly for these age groups. The provision and targeting of appropriate services requires better understanding of the characteristics and requirements of children and adolescents exposed to armed conflict. METHODS: Routine patient and programme monitoring data were analysed for patients <20 years of age attending mental health services provided by Médecins Sans Frontières (MSF) in three countries affected by armed conflict: the Democratic Republic of Congo (DRC), Iraq and the occupied Palestinian territory (oPt). The demographic characteristics, presenting mental health complaint, attributed precipitating event, services provided and short-term outcomes for mental health services users in each country are described. RESULTS: Between 2009 and 2012, 3025 individuals <20 years of age presented for care in DRC and Iraq, and in 2012 in oPt, constituting 14%, 17.5% and 51%, respectively, of all presentations to MSF mental health services in those three countries. The most common precipitating event was sexual violence in DRC (36.5%), domestic violence in Iraq (17.8%) and incarceration or detention in oPt (33%). Armed conflict-related precipitants were reported by 25.9%, 55.0% and 76.4% of youths in DRC, Iraq and oPt, respectively. The most common presenting complaints in children and adolescents were anxiety-related, followed by mood-related, behaviour-related and somatisation problems; these varied according to country and precipitating event. Although a high proportion (45.7%) left programmes early, 97% of those who completed care self-reported improvement in their presenting complaint. CONCLUSIONS: Brief trauma-focused therapy, the current MSF mental health therapeutic intervention, appears to be effective in reducing symptoms arising from the experience of trauma. Although inferences on outcomes are limited by high default rates, this provides a feasible tool for addressing the mental health needs of children exposed to armed conflict. Priorities for future research include understanding why children and adolescents constitute a small proportion of patients in some programmes, why many leave care early and how to address these issues, but this research must occur within the context of efforts to provide access to mental health services for children.


Asunto(s)
Maltrato a los Niños/terapia , Servicios de Salud Mental/estadística & datos numéricos , Guerra , Adolescente , Niño , Preescolar , República Democrática del Congo , Femenino , Investigación sobre Servicios de Salud , Humanos , Lactante , Recién Nacido , Irak , Masculino , Medio Oriente , Adulto Joven
9.
Plant Physiol Biochem ; 70: 433-44, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23835361

RESUMEN

To investigate the role of jasmonates (JAs) in the ripening of Fragaria chiloensis fruit, two concentrations of methyl jasmonate (MeJA, 10 and 100 µM) were evaluated at 2, 5 and 9 d using an in vitro ripening system. Fruit quality parameters; the contents of anthocyanin, lignin and cell wall polymers; and the transcriptional profiles of several ripening-related genes were analyzed. MeJA accelerated fruit ripening by means of a transitory increase in the soluble solid content/titratable acidity ratio, anthocyanin accumulation and an increase in softening at day 5. The expression of several phenylpropanoid-related genes, primarily those associated with anthocyanin biosynthesis, was increased under MeJA treatment, which correlated with an increased accumulation of anthocyanin. MeJA also altered the expression profiles of some cell wall-modifying genes, namely, EG1 and XTH1, and these changes correlated with a transient reduction in the firmness of MeJA-treated fruits. MeJA-responsive elements were observed in the promoter region of the EG1 gene. MeJA also increased the expression of LOX, AOS and OPR3, genes involved in the biosynthesis of JAs, and these changes correlated with the transient activation of fruit ripening observed. Conversely, the expression of ethylene and lignin biosynthesis genes (ACS, ACO, CAD and POD27) increased in MeJA-treated fruits at day 9. The present findings suggest that JAs promote the ripening of non-climacteric fruits through their involvement in anthocyanin accumulation, cell wall modification and the biosynthesis of ethylene and JAs.


Asunto(s)
Acetatos/metabolismo , Ciclopentanos/metabolismo , Fragaria/genética , Frutas/metabolismo , Regulación de la Expresión Génica de las Plantas , Expresión Génica , Genes de Plantas , Oxilipinas/metabolismo , Desarrollo de la Planta/genética , Acetatos/farmacología , Antocianinas/genética , Antocianinas/metabolismo , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Ciclopentanos/farmacología , Etilenos/biosíntesis , Fragaria/efectos de los fármacos , Fragaria/crecimiento & desarrollo , Fragaria/metabolismo , Frutas/efectos de los fármacos , Frutas/crecimiento & desarrollo , Expresión Génica/efectos de los fármacos , Lignina/biosíntesis , Lignina/genética , Oxilipinas/farmacología , Desarrollo de la Planta/efectos de los fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
10.
J Anim Sci ; 90(13): 4729-40, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23100586

RESUMEN

Predicting phenotypes is a statistical and biotechnical challenge, both in medicine (predicting an illness) and animal breeding (predicting the carcass economical value on a young living animal). High-throughput fine phenotyping is possible using metabolomics, which describes the global metabolic status of an individual, and is the closest to the terminal phenotype. The purpose of this work was to quantify the prediction power of metabolomic profiles for commonly used production phenotypes from a single blood sample from growing pigs. Several statistical approaches were investigated and compared on the basis of cross validation: raw data vs. signal preprocessing (wavelet transformation), with a single-feature selection method. The best results in terms of prediction accuracy were obtained when data were preprocessed using wavelet transformations on the Daubechies basis. The phenotypes related to meat quality were not well predicted because the blood sample was taken some time before slaughter, and slaughter is known to have a strong influence on these traits. By contrast, phenotypes of potential economic interest (e.g., lean meat percentage and ADFI) were well predicted (R(2) = 0.7; P < 0.0001) using metabolomic data.


Asunto(s)
Metabolómica/métodos , Fenotipo , Sus scrofa/genética , Sus scrofa/metabolismo , Animales , Análisis Químico de la Sangre , Cruzamiento , Femenino , Modelos Lineales , Espectroscopía de Resonancia Magnética , Masculino , Carne/normas , Metaboloma , Modelos Genéticos , Sus scrofa/crecimiento & desarrollo
12.
Clin Exp Metastasis ; 29(7): 707-27, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22798218

RESUMEN

Recent discoveries in molecular lymphology, developmental biology, and tumor biology in the context of long-standing concepts and observations on development, growth, and neoplasia implicate overlapping pathways, processes, and clinical manifestations in developmental disorders and cancer metastasis. Highlighted in this review are some of what is known (and speculated) about the genes, proteins, and signaling pathways and processes involved in lymphatic/blood vascular development in comparison to those involved in cancer progression and spread. Clues and conundra from clinical disorders that mix these processes and mute them, including embryonic rests, multicentric nests of displaced cells, uncontrolled/invasive "benign" proliferation and lymphogenous/hematogenous "spread", represent a fine line between normal development and growth, dysplasia, benign and malignant neoplasia, and "metastasis". Improved understanding of these normal and pathologic processes and their underlying pathomechanisms, e.g., stem cell origin and bidirectional epithelial-mesenchymal transition, could lead to more successful approaches in classification, treatment, and even prevention of cancer and a whole host of other diseases.


Asunto(s)
Linfangiogénesis , Metástasis Linfática , Sistema Linfático/patología , Vasos Linfáticos/patología , Neoplasias/patología , Biomarcadores de Tumor , Progresión de la Enfermedad , Transición Epitelial-Mesenquimal , Humanos , Sistema Linfático/embriología , Sistema Linfático/metabolismo , Vasos Linfáticos/embriología , Neoplasias/genética , Neoplasias/metabolismo , Transducción de Señal
14.
Rev. Asoc. Méd. Argent ; 119(1): 12-15, 2006.
Artículo en Español | BINACIS | ID: bin-6

RESUMEN

Ha sido estimado (WHO) que un 3 por ciento de la población mundial convive y padece un linfedema, entre los grados o estadios subclínico y la elefantiasis extrema. ¿Qué es el linfedema y cuál es su etiopatogenia? ¿Es un signo, un síntoma, una enfermedad? No hay duda de que el linfedema más frecuente aparece por una parasitosis. Las filariasis. Una obstrucción por una causal extrínseca del sistema linfático. Múltiples son las causas que reproducen esta situación, y el resultado, con consenso, se denomina linfedema secundario. Por oposición y no necesariamente por consenso, aparece el término linfedema primario, obstrucción funcional o anatómico por una causal intrínseca del sistema congénito, seguramente geneticamente condicionado. El término linfedema idiopático (gr) (espontáneo, de causa desconocida) aparece como una opción para definir el tema. En la medida que sea conocida la causa el termino idiopático no tiene sentido. Hoy son conocidas la mayoría de las causas pero no por qué se desencadenan. Si así fuera, todos los linfedemas tendrían tratamiento específico. Frente a una cascada de opinión y terminología se deben ordenar estos conceptos como ejercicio semántico para lograr un lenguaje común en un tema de alto impacto médico y psicosocial. (AU)


Asunto(s)
Humanos , Linfedema/clasificación , Linfedema/diagnóstico , Linfedema/etiología , Linfedema/terapia , Sistema Linfático/anomalías , Sistema Linfático/patología , Sistema Linfático/fisiología , Pediatría
15.
Rev. Asoc. Méd. Argent ; 119(1): 12-15, 2006.
Artículo en Español | BINACIS | ID: bin-119903

RESUMEN

Ha sido estimado (WHO) que un 3 por ciento de la población mundial convive y padece un linfedema, entre los grados o estadios subclínico y la elefantiasis extrema. ¿Qué es el linfedema y cuál es su etiopatogenia? ¿Es un signo, un síntoma, una enfermedad? No hay duda de que el linfedema más frecuente aparece por una parasitosis. Las filariasis. Una obstrucción por una causal extrínseca del sistema linfático. Múltiples son las causas que reproducen esta situación, y el resultado, con consenso, se denomina linfedema secundario. Por oposición y no necesariamente por consenso, aparece el término linfedema primario, obstrucción funcional o anatómico por una causal intrínseca del sistema congénito, seguramente geneticamente condicionado. El término linfedema idiopático (gr) (espontáneo, de causa desconocida) aparece como una opción para definir el tema. En la medida que sea conocida la causa el termino idiopático no tiene sentido. Hoy son conocidas la mayoría de las causas pero no por qué se desencadenan. Si así fuera, todos los linfedemas tendrían tratamiento específico. Frente a una cascada de opinión y terminología se deben ordenar estos conceptos como ejercicio semántico para lograr un lenguaje común en un tema de alto impacto médico y psicosocial. (AU)


Asunto(s)
Humanos , Linfedema/clasificación , Linfedema/diagnóstico , Linfedema/etiología , Linfedema/terapia , Sistema Linfático/anomalías , Sistema Linfático/patología , Sistema Linfático/fisiología , Pediatría
16.
Rev. Asoc. Méd. Argent ; 119(1): 12-15, 2006.
Artículo en Español | LILACS | ID: lil-431960

RESUMEN

Ha sido estimado (WHO) que un 3 por ciento de la población mundial convive y padece un linfedema, entre los grados o estadios subclínico y la elefantiasis extrema. ¿Qué es el linfedema y cuál es su etiopatogenia? ¿Es un signo, un síntoma, una enfermedad? No hay duda de que el linfedema más frecuente aparece por una parasitosis. Las filariasis. Una obstrucción por una causal extrínseca del sistema linfático. Múltiples son las causas que reproducen esta situación, y el resultado, con consenso, se denomina linfedema secundario. Por oposición y no necesariamente por consenso, aparece el término linfedema primario, obstrucción funcional o anatómico por una causal intrínseca del sistema congénito, seguramente geneticamente condicionado. El término linfedema idiopático (gr) (espontáneo, de causa desconocida) aparece como una opción para definir el tema. En la medida que sea conocida la causa el termino idiopático no tiene sentido. Hoy son conocidas la mayoría de las causas pero no por qué se desencadenan. Si así fuera, todos los linfedemas tendrían tratamiento específico. Frente a una cascada de opinión y terminología se deben ordenar estos conceptos como ejercicio semántico para lograr un lenguaje común en un tema de alto impacto médico y psicosocial.


Asunto(s)
Humanos , Linfedema/clasificación , Linfedema/diagnóstico , Linfedema/etiología , Linfedema/terapia , Sistema Linfático/anomalías , Sistema Linfático/fisiología , Sistema Linfático/patología , Pediatría
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