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1.
BJOG ; 128(12): 1928-1937, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33982856

RESUMEN

OBJECTIVE: To provide updated information about between-country variations, temporal trends and changes in inequalities within countries in caesarean delivery (CD) rates. DESIGN: Cross-sectional study of Demographic and Health Survey (DHS) during 1990-2018. SETTING: 74 low- and middle-income countries (LMICs). POPULATION: Women 15-49 years of age who had live births in the last 3 years. METHODS: Bayesian linear regression analysis was performed and absolute differences were calculated. MAIN OUTCOME MEASURE: Population-level CD by countries and sociodemographic characteristics of mothers over time. RESULTS: CD rates, based on the latest DHS rounds, varied substantially between the study countries, from 1.5% (95% CI 1.1-1.9%) in Madagascar to 58.9% (95% CI 56.0-61.6%) in the Dominican Republic. Of 62 LMICs with at least two surveys, 57 countries showed a rise in CD during 1990-2018, with the greatest increase in Sierra Leone (19.3%). Large variations in CD rates were observed across mother's wealth, residence, education and age, with a higher rate of CD by the richest and urban mothers. These inequalities have widened in many countries. Stratified analyses suggest greater provisioning of CD by the richest mothers in private facilities and poorest mothers in public facilities. CONCLUSIONS: CD rates varied substantially across geographical locations and over time, irrespective of public or private health facilities. Changes in CD rates continue across wealth, place of residence, education, and age of mother, and are widening in most study countries. TWEETABLE ABSTRACT: Increasing caesarean delivery rates were greater among the richest and urban mothers than their counterparts, with widened gaps in LMICs.


Asunto(s)
Cesárea/tendencias , Países en Desarrollo/estadística & datos numéricos , Disparidades en Atención de Salud/tendencias , Madres/estadística & datos numéricos , Adolescente , Adulto , Teorema de Bayes , Estudios Transversales , Parto Obstétrico/tendencias , Demografía , Femenino , Instituciones de Salud/estadística & datos numéricos , Humanos , Modelos Lineales , Nacimiento Vivo , Persona de Mediana Edad , Embarazo , Factores Socioeconómicos , Factores de Tiempo , Adulto Joven
2.
Cryo Letters ; 42(2): 81-86, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33970984

RESUMEN

BACKGROUND: The cryopreservation and recovery of epididymis tail sperm is an important biotechnology dependent on the composition of the freezing medium. OBJETIVE: To evaluate the effect of melatonin, added to commercial freezing medium extender, on the kinetics and viability of bovine epididymis tail sperm. MATERIAL AND METHODS: Five routines were performed, each consisting of eight epididymis and the structures were sliced onto a glass plate containing a commercial diluting medium for Botubov. The samples were divided into four groups, with 80 x 106 spermatozoa per mL. Group 1: samples diluted in Botubov. Group 2: samples centrifuged (600 g, 10 min), and the pellet re-suspended in Botubov. Group 3, samples diluted in Botubov containing 100 pM melatonin. Group 4: samples centrifuged (600 g, 10 min) and the pellet resuspended in Botubov with 100 pM melatonin. The samples were transferred to 0.5 mL straws at 40 x 106 viable spermatozoa, stabilized at 5º C for 4 h, transferred to liquid nitrogen vapour for 20 min, dipped in liquid nitrogen and stored in a cryogenic cylinder. After thawing (46ºC, 15s), sperm kinetics and viability parameters were evaluated. RESULTS: There was no difference in the parameters of total motility (MT, %), progressive motility (MP, %), progressive linear velocity (VSL, µm/s), curvilinear velocity (VCL, µm/s), linearity (LIN, %), spermatozoa with rapid movement (RAP, %) and level of intact plasma membranes and acrosome (IPMA, %) among the groups studied. However, a difference was observed between the routines performed. CONCLUSION: The protocol for freezing bovine epididymis tail sperm is applicable; however, there is an influence of the epididymis used, for the best efficacy of this biotechnology.


Asunto(s)
Antioxidantes , Criopreservación/veterinaria , Preservación de Semen , Animales , Antioxidantes/farmacología , Bovinos , Crioprotectores/farmacología , Epidídimo/citología , Masculino , Preservación de Semen/veterinaria , Motilidad Espermática , Espermatozoides
3.
Mol Psychiatry ; 23(10): 1998-2006, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29203852

RESUMEN

Stress is a well-established trigger for a number of neuropsychiatric disorders, as it alters both structure and function of several brain regions and its networks. Herein, we conduct a longitudinal neuroimaging study to assess how a chronic unpredictable stress protocol impacts the structure of the rat brain and its functional connectome in both high and low responders to stress. Our results reveal the changes that stress triggers in the brain, with structural atrophy affecting key regions such as the prelimbic, cingulate, insular and retrosplenial, somatosensory, motor, auditory and perirhinal/entorhinal cortices, the hippocampus, the dorsomedial striatum, nucleus accumbens, the septum, the bed nucleus of the stria terminalis, the thalamus and several brain stem nuclei. These structural changes are associated with increasing functional connectivity within a network composed by these regions. Moreover, using a clustering based on endocrine and behavioural outcomes, animals were classified as high and low responders to stress. We reveal that susceptible animals (high responders) develop local atrophy of the ventral tegmental area and an increase in functional connectivity between this area and the thalamus, further spreading to other areas that link the cognitive system with the fight-or-flight system. Through a longitudinal approach we were able to establish two distinct patterns, with functional changes occurring during the exposure to stress, but with an inflection point after the first week of stress when more prominent changes were seen. Finally, our study revealed differences in functional connectivity in a brainstem-limbic network that distinguishes resistant and susceptible responders before any exposure to stress, providing the first potential imaging-based predictive biomarkers of an individual's resilience/vulnerability to stressful conditions.


Asunto(s)
Encéfalo/fisiopatología , Estrés Psicológico/diagnóstico por imagen , Estrés Psicológico/fisiopatología , Animales , Biomarcadores , Conectoma/métodos , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades/diagnóstico por imagen , Estudios Longitudinales , Imagen por Resonancia Magnética/métodos , Masculino , Vías Nerviosas/diagnóstico por imagen , Ratas , Ratas Wistar , Tálamo/fisiopatología , Área Tegmental Ventral/fisiopatología
4.
Neuroimage ; 153: 86-96, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28341162

RESUMEN

The human brain presents multiple asymmetries that dynamically change throughout life. These phenomena have been associated with cognitive impairments and psychiatric disorders although possible associations with specific patterns of cognitive aging are yet to be determined. We have therefore mapped and quantified morphological asymmetries in a heterogeneous and aged population (65.2±8.0 years old, 52 male and 53 female) to explore potential associations between the asymmetries in specific brain regions and cognitive performance. The sample was characterized in a battery of neuropsychological tests and in terms of brain structural asymmetries using a ROI-based approach. A substantial number of brain areas presented some degree of asymmetry. Such biases survived a stringent statistical correction and were largely confirmed in a voxel-based analysis. In specific brain areas, like the thalamus and insula, asymmetry was correlated with cognition and mood descriptors as the Stroop words/colors test or depressive mood scale, respectively. Curiously in the latter, the association was independent of its left/right direction. Altogether, results reveal that asymmetry is widespread in the aged brain and that area-specific biases (degree and direction) associate with the functional profile of the individual.


Asunto(s)
Afecto , Encéfalo/anatomía & histología , Cognición , Lateralidad Funcional , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas
5.
Epidemiol Infect ; 145(6): 1221-1230, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28091337

RESUMEN

Pertussis epidemics have displayed substantial spatial heterogeneity in countries with high socioeconomic conditions and high vaccine coverage. This study aims to investigate the relationship between pertussis risk and socio-environmental factors on the spatio-temporal variation underlying pertussis infection. We obtained daily case numbers of pertussis notifications from Queensland Health, Australia by postal area, for the period January 2006 to December 2012. A Bayesian spatio-temporal model was used to quantify the relationship between monthly pertussis incidence and socio-environmental factors. The socio-environmental factors included monthly mean minimum temperature (MIT), monthly mean vapour pressure (VAP), Queensland school calendar pattern (SCP), and socioeconomic index for area (SEIFA). An increase in pertussis incidence was observed from 2006 to 2010 and a slight decrease from 2011 to 2012. Spatial analyses showed pertussis incidence across Queensland postal area to be low and more spatially homogeneous during 2006-2008; incidence was higher and more spatially heterogeneous after 2009. The results also showed that the average decrease in monthly pertussis incidence was 3·1% [95% credible interval (CrI) 1·3-4·8] for each 1 °C increase in monthly MIT, while average increase in monthly pertussis incidences were 6·2% (95% CrI 0·4-12·4) and 2% (95% CrI 1-3) for SCP periods and for each 10-unit increase in SEIFA, respectively. This study demonstrated that pertussis transmission is significantly associated with MIT, SEIFA, and SCP. Mapping derived from this work highlights the potential for future investigation and areas for focusing future control strategies.


Asunto(s)
Epidemias , Tos Ferina/epidemiología , Adolescente , Adulto , Anciano , Teorema de Bayes , Niño , Preescolar , Transmisión de Enfermedad Infecciosa , Ambiente , Femenino , Humanos , Humedad , Incidencia , Lactante , Recién Nacido , Persona de Mediana Edad , Embarazo , Queensland/epidemiología , Factores Socioeconómicos , Análisis Espacio-Temporal , Temperatura , Topografía Médica , Tos Ferina/transmisión , Adulto Joven
6.
Trop Med Int Health ; 21(8): 973-984, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27253178

RESUMEN

OBJECTIVE: To evaluate the association between vitamin D status and diarrhoeal episodes by enterotoxigenic (ETEC), enteropathogenic (EPEC) and enteroaggregative (EAEC) E. coli in underweight and normal-weight children aged 6-24 months in urban Bangladesh. METHODS: Cohorts of 446 normal-weight and 466 underweight children were tested separately for ETEC, EPEC and EAEC from diarrhoeal stool samples collected during 5 months of follow-up while considering vitamin D status at enrolment as the exposure. Cox proportional hazards models with unordered failure events of the same type were used to determine diarrhoeal risk factors after adjusting for sociodemographic and concurrent micronutrient status. RESULTS: Vitamin D status was not independently associated with the risk of incidence of ETEC, EPEC and EAEC diarrhoea in underweight children, but moderate-to-severe retinol deficiency was associated with reduced risk for EPEC diarrhoea upon adjustment. Among normal-weight children, insufficient vitamin D status and moderate-to-severe retinol deficiency were independently associated with 44% and 38% reduced risk of incidence of EAEC diarrhoea, respectively. These children were at higher risk of ETEC diarrhoea with vitamin D deficiency status when adjusted for micronutrient status only. CONCLUSION: This study demonstrates for the first time that normal-weight children with insufficient vitamin D status have a reduced risk of EAEC diarrhoea than children with sufficient status. Moderate-to-severe deficiency of serum retinol is associated with reduced risk of EPEC and EAEC diarrhoea in underweight and normal-weight children.

7.
Ann Hematol ; 95(2): 271-8, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26518211

RESUMEN

The introduction of agents such as thalidomide, lenalidomide, and bortezomib has changed the management of patients with multiple myeloma who are not eligible for autologous transplantation, many of whom are elderly. We sought to compare three thalidomide-based oral regimens among such patients in Latin America. We randomized patients with newly diagnosed multiple myeloma with measurable disease to one of the following regimens: melphalan, prednisone, and thalidomide (MPT); cyclophosphamide, thalidomide, and dexamethasone (CTD); and thalidomide and dexamethasone (TD). The TD arm was closed prematurely and was analyzed only descriptively. The primary endpoint was the overall response rate (ORR), whereas progression-free survival (PFS) and overall survival (OS) were secondary endpoints. The accrual rate was slower than expected, and the study was terminated after 82 patients had been randomized. The ORRs were 67.9 % with MPT, 89.7 % with CTD, and 68.7 % with TD (p = 0.056 for the comparison between MPT and CTD). The median PFS was 24.1 months for MPT, 25.9 months for CTD, and 21.5 months for TD. There were no statistically significant differences in PFS or OS between MPT and CTD. In an unplanned logistic regression analysis, ORR was significantly associated with treatment with CTD (p = 0.046) and with performance status of 0 or 1 (p = 0.035). Based on the current results, no definitive recommendations can be made regarding the comparative merit of the regimens tested. Nevertheless and until the results of further studies become available, we recommend either CTD or MPT as suitable frontline regimens for patients with multiple myeloma who are not candidates to transplantation in settings where lenalidomide and bortezomib are not available.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Trasplante de Células Madre Hematopoyéticas , Mieloma Múltiple/diagnóstico , Mieloma Múltiple/tratamiento farmacológico , Talidomida/administración & dosificación , Anciano , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Trasplante Autólogo
8.
Epidemiol Infect ; 144(16): 3494-3506, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27513886

RESUMEN

We conducted a longitudinal assessment in 466 underweight and 446 normal-weight children aged 6-24 months living in the urban slum of Dhaka, Bangladesh to determine the association between vitamin D and other micronutrient status with upper respiratory tract infection (URI) and acute lower respiratory infection (ALRI). Incidence rate ratios of URI and ALRI were estimated using multivariable generalized estimating equations. Our results indicate that underweight children with insufficient and deficient vitamin D status were associated with 20% and 23-25% reduced risk of URI, respectively, compared to children with sufficient status. Underweight children, those with serum retinol deficiency were at 1·8 [95% confidence interval (CI) 1·4-2·4] times higher risk of ALRI than those with retinol sufficiency. In normal-weight children there were no significant differences between different vitamin D status and the incidence of URI and ALRI. However, normal-weight children with zinc insufficiency and those that were serum retinol deficient had 1·2 (95% CI 1·0-1·5) times higher risk of URI and 1·9 (95% CI 1·4-2·6) times higher risk of ALRI, respectively. Thus, our results should encourage efforts to increase the intake of retinol-enriched food or supplementation in this population. However, the mechanisms through which vitamin D exerts beneficial effects on the incidence of childhood respiratory tract infection still needs further research.

9.
Food Microbiol ; 57: 103-8, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27052708

RESUMEN

This study aimed to investigate the effect of different conditions, including temperature (37 °C, 22 °C, and 4 °C), NaCl concentrations (2.5%, 4%, and 8%), and acidity (pH = 5), on the growth response of persistent and non-persistent isolates of Listeria monocytogenes. The resistance to two common sanitizers (benzalkonium chloride and hydrogen peroxide) was also investigated. A selected group of 41 persistent and non-persistent L. monocytogenes isolates recovered from three cheese processing plants during a previous longitudinal study was assembled. Average lag time was similar for persistent and non-persistent isolates grown at 37 °C, 22 °C and 4 °C but significantly shorter (p < 0.05) for persistent isolates grown at 2.5%, 4% and 8% NaCl, and at pH 5. Average growth rates were significantly higher (p < 0.05) for persistent than for non-persistent isolates when grown at 22 °C, 2.5%, 4% and 8% NaCl, and at pH 5. These results suggest that persistent strains may be better adapted to grow under stressful conditions frequently encountered in food processing environments than non-persistent strains. No relation between persistence and resistance to the tested sanitizers was found.


Asunto(s)
Desinfectantes/farmacología , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/crecimiento & desarrollo , Compuestos de Benzalconio/farmacología , Queso/microbiología , Recuento de Colonia Microbiana , Peróxido de Hidrógeno/farmacología , Concentración de Iones de Hidrógeno , Cinética , Listeria monocytogenes/química , Listeria monocytogenes/metabolismo , Cloruro de Sodio/metabolismo , Temperatura
10.
Parasitol Res ; 115(9): 3485-92, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27236650

RESUMEN

Differentiation between viable and non-viable hookworm ova in environmental samples is necessary in order to implement strategies to mitigate re-infections in endemic regions. In this study, an untargeted metabolic profiling method was developed that utilised gas chromatography-mass spectrometry (GC-MS) in order to investigate hookworm ova viability. Ancylostoma caninum was used to investigate the metabolites within viable and non-viable ova. Univariate and multivariate statistical analyses of the data resulted in the identification of 53 significant metabolites across all hookworm ova samples. The major compounds observed in viable and non-viable hookworm ova were tetradecanoic acid, commonly known as myristic acid [fold change (FC) = 0.4], and dodecanoic acid, commonly known as lauric acid (FC = 0.388). Additionally, the viable ova had self-protecting metabolites such as prostaglandins, a typical feature absent in non-viable ova. The results of this study demonstrate that metabolic profiling using GC-MS methods can be used to determine the viability of canine hookworm ova. Further studies are needed to assess the applicability of metabolic profiling using GC-MS to detect viable hookworm ova in the mixed (viable and non-viable) populations from environmental samples and identify the metabolites specific to human hookworm species.


Asunto(s)
Ancylostoma/metabolismo , Anquilostomiasis/veterinaria , Enfermedades de los Perros/parasitología , Metaboloma/fisiología , Óvulo/fisiología , Ancylostoma/fisiología , Anquilostomiasis/parasitología , Anquilostomiasis/patología , Animales , Perros , Heces/parasitología , Cromatografía de Gases y Espectrometría de Masas , Humanos , Ácidos Láuricos/metabolismo , Ácido Mirístico/metabolismo , Prostaglandinas/metabolismo
11.
Undersea Hyperb Med ; 43(1): 71-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27000016

RESUMEN

The U.S. territory of Guam attracts thousands of military and civilian divers annually and is home to the only recompression facility within a 5,000-km radius that accepts critically injured dive casualties. As recompression chambers are confined spaces and standard use of electrical cardioversion cannot be used, cardiac resuscitation at depth must deviate from advanced cardiovascular life support (ACLS) algorithms. Furthermore, many hyperbaric chambers that accept dive casualties are in remote locations, a situation that requires providers to approach cardiac resuscitation in a different way when compared to an in-hospital or ICU setting. This presents a challenge to trained medical and diving professionals. We present two contrasting vignettes of diving injuries initially responsive to appropriate treatment but then deteriorating during recompression therapy and ultimately requiring resuscitation at depth. Additionally, we explore the physiologic basis of resuscitation in a hyperbaric environment as it relates to the treatment of cardiac arrest at depth. This review critically examines the current guidelines in place for emergency cardiac resuscitation in a hyperbaric chamber followed by recommendations for the key steps in the sequence of care.


Asunto(s)
Reanimación Cardiopulmonar/métodos , Enfermedad de Descompresión/complicaciones , Buceo/efectos adversos , Paro Cardíaco/terapia , Oxigenoterapia Hiperbárica , Adulto , Antiarrítmicos/administración & dosificación , Presión Atmosférica , Cardioversión Eléctrica , Urgencias Médicas , Epinefrina/administración & dosificación , Resultado Fatal , Guam , Paro Cardíaco/etiología , Humanos , Masculino , Agua de Mar
12.
Br J Dermatol ; 173(4): 998-1005, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26132494

RESUMEN

BACKGROUND: Psoriasis is a chronic inflammatory disease that affects the skin. CD4(+) CD28(null) cells are a subset of T lymphocytes associated with systemic inflammation and increased cardiovascular disease risk, and may be involved in the pathogenesis of psoriasis. OBJECTIVES: To study the features of circulating CD4(+) CD28(null) cells in patients with psoriasis, adjusted for the influence of known cardiovascular disease risk factors. METHODS: Forty-two patients with psoriasis and 42 controls entered the study. Peripheral blood mononuclear cells were analysed for the frequency of CD4(+) CD28(null) T lymphocytes and their expression of cytotoxic granules and homing receptors. Immunostaining for cutaneous cytotoxic granules was assessed in skin biopsies from 11 patients. RESULTS: There were no differences in the frequency of CD4(+) CD28(null) T cells between groups in all situations analysed. However, there was an increased number of cells expressing cytotoxic granules and a decreased number expressing CXCR3 in ex vivo samples of patients with psoriasis. A negative correlation was observed between the frequency of ex vivo CD4(+) CD28(null) cells and psoriasis severity. After clinical remission in nine patients, ex vivo CD4(+) CD28(null) lymphocytes expressing cytotoxic granules decreased. Perforin-, granzyme B- and granulysin-containing cells were found in skin lesions. Patients with psoriasis also had increased plasma levels of C-reactive protein. CONCLUSIONS: These data suggest that cytotoxic cells, such as CD4(+) CD28(null) lymphocytes, within an inflammatory environment may play a role in the pathogenesis of psoriasis.


Asunto(s)
Antígenos CD28/metabolismo , Linfocitos T CD4-Positivos/inmunología , Psoriasis/inmunología , Linfocitos T/inmunología , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Psoriasis/tratamiento farmacológico , Receptores CXCR3/metabolismo , Inducción de Remisión
13.
Euro Surveill ; 20(17)2015 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-25955775

RESUMEN

In Portugal, listeriosis has been notifiable since April 2014, but there is no active surveillance programme for the disease. A retrospective study involving 25 national hospitals led to the detection of an outbreak that occurred between March 2009 and February 2012. The amount of time between the start of the outbreak and its detection was 16 months. Of the 30 cases of listeriosis reported, 27 were in the Lisbon and Vale do Tejo region. Two cases were maternal/neonatal infections and one resulted in fetal loss. The mean age of the non-maternal/neonatal cases was 59 years (standard deviation: 17); 13 cases were more than 65 years old. The case fatality rate was 36.7%. All cases were caused by molecular serogroup IVb isolates indistinguishable by pulsed-field gel electrophoresis and ribotype profiles. Collaborative investigations with the national health and food safety authorities identified cheese as the probable source of infection, traced to a processing plant. The magnitude of this outbreak, the first reported food-borne listeriosis outbreak in Portugal, highlights the importance of having an effective listeriosis surveillance system in place for early detection and resolution of outbreaks, as well as the need for a process for the prompt submission of Listeria monocytogenes isolates for routine laboratory typing.


Asunto(s)
Queso/virología , Brotes de Enfermedades , Contaminación de Alimentos/análisis , Enfermedades Transmitidas por los Alimentos/epidemiología , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Adolescente , Adulto , Anciano , Electroforesis en Gel de Campo Pulsado , Femenino , Microbiología de Alimentos , Inocuidad de los Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Listeria monocytogenes/clasificación , Listeria monocytogenes/genética , Listeriosis/microbiología , Persona de Mediana Edad , Portugal/epidemiología , Estudios Retrospectivos , Ribotipificación , Vigilancia de Guardia , Serotipificación
14.
ScientificWorldJournal ; 2015: 467178, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25834836

RESUMEN

Schizophrenia stands for a long-lasting state of mental uncertainty that may bring to an end the relation among behavior, thought, and emotion; that is, it may lead to unreliable perception, not suitable actions and feelings, and a sense of mental fragmentation. Indeed, its diagnosis is done over a large period of time; continuos signs of the disturbance persist for at least 6 (six) months. Once detected, the psychiatrist diagnosis is made through the clinical interview and a series of psychic tests, addressed mainly to avoid the diagnosis of other mental states or diseases. Undeniably, the main problem with identifying schizophrenia is the difficulty to distinguish its symptoms from those associated to different untidiness or roles. Therefore, this work will focus on the development of a diagnostic support system, in terms of its knowledge representation and reasoning procedures, based on a blended of Logic Programming and Artificial Neural Networks approaches to computing, taking advantage of a novel approach to knowledge representation and reasoning, which aims to solve the problems associated in the handling (i.e., to stand for and reason) of defective information.


Asunto(s)
Redes Neurales de la Computación , Esquizofrenia/diagnóstico , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Predisposición Genética a la Enfermedad , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Esquizofrenia/genética , Adulto Joven
16.
J Environ Manage ; 134: 15-9, 2014 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-24463731

RESUMEN

Some aluminosilicates, for example mullite and wollastonite, are very important in the ceramic and construction industries. The most significant glass-ceramic for building applications has wollastonite as the main crystal phase. In this work we report on the use of sugarcane bagasse ash (SCBA) to produce glass-ceramics with silicates as the major crystalline phases. The glasses (frits) were prepared by mixing ash, limestone (calcium and magnesium carbonates) and potassium carbonate as the fluxing agent. X-ray fluorescence was used to determine the chemical composition of the glasses and their crystallization was assessed by using thermal analysis (DTA/DSC/TGA) and X-ray diffraction. The results showed that glass-ceramic material can be produced with wollastonite as the major phase, at a temperature lower than 900 °C.


Asunto(s)
Celulosa , Cerámica , Materiales de Construcción , Saccharum , Carbonato de Calcio/química , Rastreo Diferencial de Calorimetría , Carbonatos/química , Cristalización , Potasio/química , Reciclaje/métodos , Termogravimetría , Residuos , Difracción de Rayos X
17.
Int Endod J ; 46(5): 458-65, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23078183

RESUMEN

AIM: To compare the flexibility, torsional resistance and structural and dimensional characteristics of instruments produced by twisting with those of a geometrically similar nickel-titanium (NiTi) system produced by a grinding process. METHODOLOGY: The mean diameters along the flute and the pitch length of size 25, .04 taper, size 25, .06 taper, and size 25, .08 taper Twisted File (TF) (SybronEndo, Orange, CA, USA), and size 25, .04 taper, and size 25, .06 taper RaCe instruments (FKG, La Chaux-de-Fonds, Switzerland) (n = 10 each) were measured according to ANSI/ADA specification No. 101. Two pairs of instruments were found to have similar diameters at 3 mm from the tip: TF size 25, .06 taper and RaCe size 25, .04 taper, and TF size 25, .08 taper and RaCe size 25, .06 taper. The cross-sectional areas at 3 mm from the tip were determined. These instruments were then submitted to energy-dispersive X-ray spectroscopy, X-ray diffraction, differential scanning calorimetry (DSC), and Vickers microhardness measurements. Bending moment at 45° and maximum torque at fracture were measured (n = 10) according to specification ISO 3630-1. Data were analysed using analysis of variance (α = 0.05). RESULTS: The two types of instruments had approximately the same chemical composition, phase constitution, and austenite finishing temperatures. TF instruments had significantly (P ≤ 0.001) lower Vickers microhardness values and were more flexible than RaCe instruments (P = 0.016), but had similar (TF size 25, .08 taper and RaCe size 25, .06 taper, P = 0.916) or significantly higher (TF size 25, .06 taper and RaCe size 25, .04 taper, P ≤ 0.001) torsional resistance. CONCLUSIONS: Comparison of TF and RaCe instruments of similar measured dimensions revealed that the different manufacturing methods employed for producing these instruments gave rise to different mechanical behaviours.


Asunto(s)
Aleaciones Dentales/química , Níquel/química , Preparación del Conducto Radicular/instrumentación , Titanio/química , Rastreo Diferencial de Calorimetría , Elasticidad , Diseño de Equipo , Dureza , Humanos , Ensayo de Materiales , Fenómenos Mecánicos , Fenómenos Físicos , Docilidad , Espectrometría por Rayos X , Propiedades de Superficie , Torque , Torsión Mecánica , Difracción de Rayos X
18.
Eur Respir J ; 39(2): 254-64, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21700603

RESUMEN

It has recently been suggested that regular exercise reduces lung function decline and risk of chronic obstructive pulmonary disease (COPD) among active smokers; however, the mechanisms involved in this effect remain poorly understood. The present study evaluated the effects of regular exercise training in an experimental mouse model of chronic cigarette smoke exposure. Male C57BL/6 mice were divided into four groups (control, exercise, smoke and smoke+exercise). For 24 weeks, we measured respiratory mechanics, mean linear intercept, inflammatory cells and reactive oxygen species (ROS) in bronchoalveolar lavage (BAL) fluid, collagen deposition in alveolar walls, and the expression of antioxidant enzymes, matrix metalloproteinase 9, tissue inhibitor of metalloproteinase (TIMP)1, interleukin (IL)-10 and 8-isoprostane in alveolar walls. Exercise attenuated the decrease in pulmonary elastance (p<0.01) and the increase in mean linear intercept (p=0.003) induced by cigarette smoke exposure. Exercise substantially inhibited the increase in ROS in BAL fluid and 8-isoprostane expression in lung tissue induced by cigarette smoke. In addition, exercise significantly inhibited the decreases in IL-10, TIMP1 and CuZn superoxide dismutase induced by exposure to cigarette smoke. Exercise also increased the number of cells expressing glutathione peroxidase. Our results suggest that regular aerobic physical training of moderate intensity attenuates the development of pulmonary disease induced by cigarette smoke exposure.


Asunto(s)
Estrés Oxidativo/fisiología , Condicionamiento Físico Animal/fisiología , Enfermedad Pulmonar Obstructiva Crónica , Mecánica Respiratoria/fisiología , Contaminación por Humo de Tabaco/efectos adversos , Animales , Antioxidantes/metabolismo , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Dinoprost/análogos & derivados , Dinoprost/metabolismo , Enfisema/etiología , Enfisema/fisiopatología , Enfisema/prevención & control , Interleucina-10/metabolismo , Macrófagos Alveolares/metabolismo , Masculino , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , Alveolos Pulmonares/metabolismo , Alveolos Pulmonares/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/etiología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/prevención & control , Especies Reactivas de Oxígeno/metabolismo , Inhibidor Tisular de Metaloproteinasa-1/metabolismo
19.
Food Microbiol ; 30(1): 24-8, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22265279

RESUMEN

The effects of previous exposure to sub-lethal acidic and osmotic stresses on the survival of Listeria monocytogenes during exposure to gastro-intestinal (GI) tract simulation, was investigated. Six L. monocytogenes strains isolated from cheeses were selected and exposed to high salt concentrations or acidic conditions and their viability compared in quick and slow digestions. The results demonstrated that (i) all isolates were more sensitive to the exposure to acidic than to osmotic sub-lethal conditions (ii) significant differences (p < 0.05) between the two types of digestion were observed; in slow digestion, the log reduction was higher for all the tested isolates (iii) all isolates were inhibited in the presence of bile salts for both types of digestion (iv) differences between quick and slow digestion were not observed (p > 0.05) after exposure to either osmotic or acidic stress (v) a higher cellular inactivation (p < 0.001) was observed during the passage through the GI tract simulation after exposure to osmotic than to acidic stresses and (vi) neither osmotic nor acidic sub-lethal stresses conferred resistance to simulated GI tract conditions.


Asunto(s)
Contaminación de Alimentos , Microbiología de Alimentos/métodos , Tracto Gastrointestinal/microbiología , Listeria monocytogenes/crecimiento & desarrollo , Estrés Fisiológico , Queso/microbiología , Recuento de Colonia Microbiana , Conservación de Alimentos , Concentración de Iones de Hidrógeno , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/aislamiento & purificación , Viabilidad Microbiana , Cloruro de Sodio/análisis
20.
Aust Vet J ; 100(7): 296-305, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35582949

RESUMEN

The largest Australian farm-based outbreak of Q fever originated from a dairy goat herd. We surveyed commercial dairy goat farms across Australia by testing bulk tank milk (BTM) samples using a commercial indirect enzyme-linked immunosorbent assay and two quantitative polymerase chain reactions (PCRs). Of the 66 commercial dairy goat herds on record, managers from 61 herds were contacted and 49 provided BTM samples. Five of the surveyed herds were positive on at least one of the diagnostic tests, thus herd-level apparent prevalence was 10% (95% confidence interval [CI] 4 to 22). True prevalence was estimated to be 3% (95% credible interval: 0 to 18). Herd managers completed a questionnaire on herd management, biosecurity and hygiene practices and risk factors were investigated using multivariable logistic regression. Herds with >900 milking does (the upper quartile) were more likely to be Coxiella burnetii positive (odds ratio = 6.75; 95% CI 1.65 to 27.7) compared with farms with ≤900 milking does. The odds of BTM positivity increased by a factor of 2.53 (95% CI 1.51 to 4.22) for each order of magnitude increase in the number of goats per acre. C. burnetii was not detected in samples from the majority of the Australian dairy goat herds suggesting there is an opportunity to protect the industry and contain this disease with strengthened biosecurity practices. Intensification appeared associated with an increased risk of positivity. Further investigation is required to discriminate the practices associated with an increased risk of introduction to disease-free herds, from practices associated with maintenance of C. burnetii infection in infected dairy goat herds.


Asunto(s)
Enfermedades de los Bovinos , Coxiella burnetii , Enfermedades de las Cabras , Animales , Australia/epidemiología , Bovinos , Enfermedades de los Bovinos/epidemiología , Estudios Transversales , Industria Lechera , Ensayo de Inmunoadsorción Enzimática/veterinaria , Granjas , Enfermedades de las Cabras/epidemiología , Cabras , Leche , Prevalencia , Factores de Riesgo
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