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1.
PLoS Comput Biol ; 19(8): e1011007, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37535694

RESUMEN

The thalamus is a central brain structure that serves as a relay station for sensory inputs from the periphery to the cortex and regulates cortical arousal. Traditionally, it has been regarded as a passive relay that transmits information between brain regions. However, recent studies have suggested that the thalamus may also play a role in shaping functional connectivity (FC) in a task-based context. Based on this idea, we hypothesized that due to its centrality in the network and its involvement in cortical activation, the thalamus may also contribute to resting-state FC, a key neurological biomarker widely used to characterize brain function in health and disease. To investigate this hypothesis, we constructed ten in-silico brain network models based on neuroimaging data (MEG, MRI, and dwMRI), and simulated them including and excluding the thalamus, and raising the noise into thalamus to represent the afferences related to the reticular activating system (RAS) and the relay of peripheral sensory inputs. We simulated brain activity and compared the resulting FC to their empirical MEG counterparts to evaluate model's performance. Results showed that a parceled version of the thalamus with higher noise, able to drive damped cortical oscillators, enhanced the match to empirical FC. However, with an already active self-oscillatory cortex, no impact on the dynamics was observed when introducing the thalamus. We also demonstrated that the enhanced performance was not related to the structural connectivity of the thalamus, but to its higher noisy inputs. Additionally, we highlighted the relevance of a balanced signal-to-noise ratio in thalamus to allow it to propagate its own dynamics. In conclusion, our study sheds light on the role of the thalamus in shaping brain dynamics and FC in resting-state and allowed us to discuss the general role of criticality in the brain at the mesoscale level.


Asunto(s)
Encéfalo , Tálamo , Encéfalo/fisiología , Tálamo/diagnóstico por imagen , Tálamo/fisiología , Imagen por Resonancia Magnética/métodos , Tronco Encefálico , Mapeo Encefálico/métodos , Vías Nerviosas/fisiología
2.
Infection ; 52(4): 1315-1324, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38353873

RESUMEN

PURPOSE: Leishmaniasis, caused by the parasite of the genus Leishmania, is a neglected tropical disease which is endemic in more than 60 countries. In South-East Asia, Brazil, and East Africa, it mainly occurs as kala-azar (visceral leishmaniasis, VL), and subsequently as post kala-azar dermal leishmaniasis (PKDL) in a smaller portion of cases. As stated per WHO roadmap, accessibility to accurate diagnostic methods is an essential step to achieve elimination. This study aimed to test the accuracy of a portable minoo device, a small battery-driven, multi-use fluorimeter operating with isothermal technology for molecular diagnosis of VL and PKDL. METHODS: Fluorescence data measured by the device within 20 min are reported back to the mobile application (or app) via Bluetooth and onward via the internet to a backend. This allows anonymous analysis and storage of the test data. The test result is immediately returned to the app displaying it to the user. RESULTS: The limit of detection was 11.2 genome copies (95% CI) as determined by screening a tenfold dilution range of whole Leishmania donovani genomes using isothermal recombinase polymerase amplification (RPA). Pathogens considered for differential diagnosis were tested and no cross-reactivity was observed. For its diagnostic performance, DNA extracted from 170 VL and PKDL cases, comprising peripheral blood samples (VL, n = 96) and skin biopsies (PKDL, n = 74) from India (n = 108) and Bangladesh (n = 62), was screened. Clinical sensitivity and specificity were 88% and 91%, respectively. CONCLUSION: Minoo devices can offer a convenient, cheaper alternative to other molecular diagnostics. Its easy handling makes it ideal for use in low-resource settings to identify parasite burden.


Asunto(s)
Técnicas de Diagnóstico Molecular , Teléfono Inteligente , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/instrumentación , Sensibilidad y Especificidad , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/parasitología , Leishmania/aislamiento & purificación , Leishmania/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Amplificación de Ácido Nucleico/instrumentación , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/parasitología , Leishmania donovani/genética , Leishmania donovani/aislamiento & purificación
3.
J Clin Immunol ; 43(5): 921-932, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36821021

RESUMEN

BACKGROUND: Cryptococcosis is a potentially life-threatening fungal disease caused by encapsulated yeasts of the genus Cryptococcus, mostly C. neoformans or C. gattii. Cryptococcal meningitis is the most frequent clinical manifestation in humans. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) have recently been discovered in otherwise healthy adult patients with cryptococcal meningitis, mostly caused by C. gattii. We hypothesized that three Colombian patients with cryptococcal meningitis caused by C. neoformans in two of them would carry high plasma levels of neutralizing auto-Abs against GM-CSF. METHODS: We reviewed medical and laboratory records, performed immunological evaluations, and tested for anti-cytokine auto-Abs three previously healthy HIV-negative adults with disseminated cryptococcosis. RESULTS: Peripheral blood leukocyte subset levels and serum immunoglobulin concentrations were within the normal ranges. We detected high levels of neutralizing auto-Abs against GM-CSF in the plasma of all three patients. CONCLUSIONS: We report three Colombian patients with disseminated cryptococcosis associated with neutralizing auto-Abs against GM-CSF. Further studies should evaluate the genetic contribution to anti-GM-CSF autoantibody production and the role of the GM-CSF signaling pathway in the immune response to Cryptococcus spp.


Asunto(s)
Criptococosis , Cryptococcus neoformans , Meningitis Criptocócica , Adulto , Humanos , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Meningitis Criptocócica/diagnóstico , Autoanticuerpos , Colombia , Criptococosis/diagnóstico
4.
Demography ; 60(1): 327-342, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36705545

RESUMEN

Everyone has a chronological age. Because survivorship declines relentlessly in populations with age-specific death rates greater than zero, everyone also has a survivorship age ("s-age"), the age at which a proportion s of the population is still alive. S-ages can be estimated for both periods and cohorts. While trajectories of mortality over chronological ages differ (e.g., across populations, over time, by sex, or by any subpopulation), mortality trajectories over s-ages are similar, a sign that populations experience similar mortality dynamics at specific levels of survivorship. We show that this important demographic regularity holds for 23 sex-specific populations analyzed during a period comprising more than 100 years.


Asunto(s)
Envejecimiento , Mortalidad , Femenino , Humanos , Masculino
5.
Allergol Immunopathol (Madr) ; 50(4): 129-136, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35789412

RESUMEN

INTRODUCTION: Common variable immunodeficiency (CVID) is the most prevalent symptomatic humoral deficiency; however, its heterogeneous presentation makes the diagnosis difficult. The present study is aimed to verify the CVID diagnostic criteria as established by the European Society for Immunodeficiencies in 42 CVID patients from our outpatient clinic. METHODS: Information was collected from their medical records and when needed, lymphocyte subpopulations in peripheral blood (PB) were performed by flow cytometry. RESULTS: All the patients fulfilled the clinical working definition for CVID and showed decreased serum IgG and IgA at diagnosis. Over two-thirds of the patients had decreased memory B cell percentages. However, the remaining patients exhibited other quantitative B cell defects in PB. Evaluation of vaccination responses was only found in 13 records and 69% were not responsive. None of the patients were subjected to vaccination studies to both, T-cell dependent and independent antigens. The two required tests to evaluate T cell responses were performed in 84.2% of the patients and reported normal. Without the support of third-party payers, only 34.2% of our patients would have completed the required evaluations. CONCLUSIONS: Further efforts are needed to speed up CVID diagnosis in low-resourced settings, increasing the availability of the required resources and optimizing the healthcare supply chain.


Asunto(s)
Inmunodeficiencia Variable Común , Linfocitos B , Inmunodeficiencia Variable Común/diagnóstico , Citometría de Flujo , Humanos , Subgrupos Linfocitarios , Linfocitos T
6.
BMC Geriatr ; 21(1): 406, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34210289

RESUMEN

BACKGROUND: The existence of a super-select group of centenarians that demonstrates increased survivorship has been hypothesized. However, it is unknown if this super-select group possesses similar characteristics apart from extreme longevity. METHODS: In this study, we analyse high-quality health and survival data of Danish centenarians born in 1895, 1905 and 1910. We use Latent Class Analysis to identify unobserved health classes and to test whether these super-select lives share similar health characteristics. RESULTS: We find that, even after age 100, a clear and distinct gradient in health exists and that this gradient is remarkably similar across different birth cohorts of centenarians. Based on the level of health, we identify three clusters of centenarians - robust, frail and intermediate - and show that these groups have different survival prospects. The most distinctive characteristic of the robust centenarians is the outperformance in different health dimensions (physical, functional and cognitive). Finally, we show that our health class categorizations are good predictors of the survival prospects of centenarians. CONCLUSIONS: There is a clear stratification in health and functioning among those over 100 years of age and these differences are associated with survival beyond age 100.


Asunto(s)
Longevidad , Anciano de 80 o más Años , Dinamarca/epidemiología , Humanos
7.
Optom Vis Sci ; 98(11): 1279-1286, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34510143

RESUMEN

SIGNIFICANCE: A base-down prism was incorporated on the anterior surface of rigid gas-permeable (RGP) contact lenses to explore potential effects on the residual ocular aberrations after contact lens fitting in keratoconic eyes. PURPOSE: This study aimed to evaluate the correction of ocular aberrations with corneal prismatic RGP contact lenses in keratoconic eyes and their impact on visual function. METHODS: A cross-sectional and randomized study was performed. Seventeen eyes of 17 keratoconus patients (34.6 ± 11.1 years) were evaluated. Two designs (standard and prismatic) of a corneal RGP contact lens (KAKC; Conoptica, Barcelona, Spain) were fitted to the same eye of each patient in a random order: a standard RGP contact lens as control and a prismatic RGP contact lens with a base-down prism of 1.6 prism diopters. Ocular aberrations were measured for a pupil diameter of 3 mm with and without both contact lenses, whereas high-contrast distance visual acuity, low-contrast distance visual acuity, and contrast sensitivity were measured under photopic and mesopic conditions. RESULTS: Both contact lenses improved oblique primary astigmatism, defocus, vertical coma, coma-like, and root-mean-square higher-order aberrations compared with the unaided eyes (P < .05). Furthermore, the prismatic RGP contact lenses offered lower values of vertical coma and root-mean-square higher-order aberrations than the standard RGP contact lenses (P < .05). Both designs (standard and prismatic) produced a positive vertical coma of lower magnitude than the negative vertical coma of the unaided eyes. On the other hand, the improvement achieved in all visual function variables was the same for both contact lens designs (P ≥ .05). CONCLUSIONS: The prismatic RGP contact lenses corrected higher levels of higher-order aberrations compared with the standard RGP contact lenses. However, both contact lens designs with the same refractive power were equally efficient at improving visual function.


Asunto(s)
Lentes de Contacto , Queratocono , Adulto , Estudios Transversales , Humanos , Queratocono/terapia , Persona de Mediana Edad , Refracción Ocular , Agudeza Visual
8.
BMC Oral Health ; 21(1): 179, 2021 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-33827530

RESUMEN

BACKGROUND: The aim of this study was to compare the influence of two novel reciprocating movements on the cyclic fatigue resistance of endodontic reciprocating files. METHODS: 30 Procodile® (Komet Medical, Lemgo, Germany) files were selected in this study and distributed according to the following study groups depending on the movements to be performed: ReFlex Dynamic (n = 10), ReFlex Smart (n = 10) and Reciproc (n = 10) reciprocating movement. These files were fixed to a specific dynamic cyclic fatigue device designed and manufactured by 3D impression to simulate the pecking motion performed by the operator. The time to failure and the number of cycles of in-and-out of the endodontic files was registered. The results were analyzed by ANOVA and Weibull statistics. RESULTS: Statistically significant differences were found when the number of cycles of in-and-out movement and the time to failure of ReFlex Dynamic and Reciproc reciprocating movement (p < 0.001) and between ReFlex Smart and Reciproc reciprocating movement (p < 0.001) were compared in pairs. However, no statistically significant differences were observed between time to failure and number of cycles of in-and-out movement of ReFlex Dynamic and ReFlex Smart reciprocating movement (p = 0.253). CONCLUSIONS: The ReFlex Smart reciprocating movement increased the cyclic fatigue resistance of endodontic reciprocating files compared with traditional reciprocating movement.


Asunto(s)
Preparación del Conducto Radicular , Titanio , Diseño de Equipo , Falla de Equipo , Alemania , Humanos , Ensayo de Materiales
9.
Blood ; 132(22): 2362-2374, 2018 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-30254128

RESUMEN

ARPC1B is a key factor for the assembly and maintenance of the ARP2/3 complex that is involved in actin branching from an existing filament. Germline biallelic mutations in ARPC1B have been recently described in 6 patients with clinical features of combined immunodeficiency (CID), whose neutrophils and platelets but not T lymphocytes were studied. We hypothesized that ARPC1B deficiency may also lead to cytoskeleton and functional defects in T cells. We have identified biallelic mutations in ARPC1B in 6 unrelated patients with early onset disease characterized by severe infections, autoimmune manifestations, and thrombocytopenia. Immunological features included T-cell lymphopenia, low numbers of naïve T cells, and hyper-immunoglobulin E. Alteration in ARPC1B protein structure led to absent/low expression by flow cytometry and confocal microscopy. This molecular defect was associated with the inability of patient-derived T cells to extend an actin-rich lamellipodia upon T-cell receptor (TCR) stimulation and to assemble an immunological synapse. ARPC1B-deficient T cells additionally displayed impaired TCR-mediated proliferation and SDF1-α-directed migration. Gene transfer of ARPC1B in patients' T cells using a lentiviral vector restored both ARPC1B expression and T-cell proliferation in vitro. In 2 of the patients, in vivo somatic reversion restored ARPC1B expression in a fraction of lymphocytes and was associated with a skewed TCR repertoire. In 1 revertant patient, memory CD8+ T cells expressing normal levels of ARPC1B displayed improved T-cell migration. Inherited ARPC1B deficiency therefore alters T-cell cytoskeletal dynamics and functions, contributing to the clinical features of CID.


Asunto(s)
Complejo 2-3 Proteico Relacionado con la Actina/genética , Mutación de Línea Germinal , Síndromes de Inmunodeficiencia/genética , Linfocitos T/patología , Complejo 2-3 Proteico Relacionado con la Actina/química , Femenino , Homocigoto , Humanos , Síndromes de Inmunodeficiencia/patología , Masculino , Modelos Moleculares , Linaje , Conformación Proteica , Inmunodeficiencia Combinada Grave/genética , Inmunodeficiencia Combinada Grave/patología , Linfocitos T/metabolismo
10.
BMC Public Health ; 20(1): 39, 2020 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-31924192

RESUMEN

BACKGROUND: Of all lifestyle behaviours, smoking caused the most deaths in the last century. Because of the time lag between the act of smoking and dying from smoking, and because males generally take up smoking before females do, male and female smoking epidemiology often follows a typical double wave pattern dubbed the 'smoking epidemic'. How are male and female deaths from this epidemic differentially progressing in high-income regions on a cohort-by-age basis? How have they affected male-female survival differences? METHODS: We used data for the period 1950-2015 from the WHO Mortality Database and the Human Mortality Database on three geographic regions that have progressed most into the smoking epidemic: high-income North America, high-income Europe and high-income Oceania. We examined changes in smoking-attributable mortality fractions as estimated by the Preston-Glei-Wilmoth method by age (ages 50-85) across birth cohorts 1870-1965. We used these to trace sex differences with and without smoking-attributable mortality in period life expectancy between ages 50 and 85. RESULTS: In all three high-income regions, smoking explained up to 50% of sex differences in period life expectancy between ages 50 and 85 over the study period. These sex differences have declined since at least 1980, driven by smoking-attributable mortality, which tended to decline in males and increase in females overall. Thus, there was a convergence between sexes across recent cohorts. While smoking-attributable mortality was still increasing for older female cohorts, it was declining for females in the more recent cohorts in the US and Europe, as well as for males in all three regions. CONCLUSIONS: The smoking epidemic contributed substantially to the male-female survival gap and to the recent narrowing of that gap in high-income North America, high-income Europe and high-income Oceania. The precipitous decline in smoking-attributable mortality in recent cohorts bodes somewhat hopeful. Yet, smoking-attributable mortality remains high, and therefore cause for concern.


Asunto(s)
Países Desarrollados/estadística & datos numéricos , Epidemias , Disparidades en el Estado de Salud , Fumar/epidemiología , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Bases de Datos Factuales , Europa (Continente)/epidemiología , Femenino , Humanos , Esperanza de Vida/tendencias , Masculino , Persona de Mediana Edad , América del Norte/epidemiología , Oceanía/epidemiología , Distribución por Sexo , Fumar/mortalidad , Análisis de Supervivencia
11.
Popul Stud (Camb) ; 74(1): 75-92, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31179848

RESUMEN

It is uncertain whether Latin America and Caribbean (LAC) countries are approaching a single mortality regime. Over the last three decades, LAC has experienced major public health interventions and the highest number of homicides in the world. However, these interventions and homicide rates are not evenly shared across countries. This study documents trends in life expectancy and lifespan variability for 20 LAC countries, 2000-14. By extending a previous method, we decompose differences in lifespan variability between LAC and a developed world benchmark into cause-specific effects. For both sexes, dispersion of amenable diseases through the age span makes the largest contribution to the gap between LAC and the benchmark. Additionally, for males, the concentration of homicides, accidents, and suicides in mid-life further impedes mortality convergence. Great disparity exists in the region: while some countries are rapidly approaching the developed regime, others remain far behind and suffer a clear disadvantage in population health.


Asunto(s)
Países en Desarrollo/estadística & datos numéricos , Esperanza de Vida/tendencias , Mortalidad/tendencias , Accidentes/mortalidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Región del Caribe/epidemiología , Causas de Muerte/tendencias , Niño , Mortalidad del Niño/tendencias , Preescolar , Femenino , Homicidio/estadística & datos numéricos , Humanos , Lactante , Mortalidad Infantil/tendencias , Recién Nacido , América Latina/epidemiología , Longevidad , Masculino , Persona de Mediana Edad , Distribución por Sexo , Factores Socioeconómicos , Suicidio/estadística & datos numéricos , Adulto Joven
12.
Molecules ; 25(14)2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32679820

RESUMEN

Plant cell and organ cultures of Helianthella quinquenervis, a medicinal plant whose roots are used by the Tarahumara Indians of Chihuahua, Mexico, to relieve several ailments, were established to identify and quantify some chromenes with biological activity, such as encecalin, and to evaluate their potential for biotechnological production. Gas chromatography-mass spectrometry (GC-MS) analysis corroborated the presence of quantifiable amounts of encecalin in H. quinquenervis cell cultures (callus and cell suspensions). In addition, hairy roots were obtained through three transformation protocols (prick, 45-s sonication and co-culture), using wild type Agrobacterium rhizogenes A4. After three months, cocultivation achieved the highest percentage of transformation (66%), and a comparable production (FW) of encecalin (110 µg/g) than the sonication assay (120 µg/g), both giving far higher yields than the prick assay (19 µg/g). Stable integration of rolC and aux1 genes in the transformed roots was confirmed by polymerase chain reaction (PCR). Hairy roots from cocultivation (six months-old) accumulated as much as 1086 µg/g (FW) of encecalin, over three times higher than the cell suspension cultures. The production of encecalin varied with growth kinetics, being higher at the stationary phase. This is the first report of encecalin production in hairy roots of H. quinquenervis, demonstrating the potential for a future biotechnological production of chromenes.


Asunto(s)
Cistaceae/metabolismo , Fitoquímicos/metabolismo , Raíces de Plantas/química , Plantas Medicinales/metabolismo , Agrobacterium , Células Cultivadas , Cromatografía de Gases y Espectrometría de Masas , Germinación , Fitoquímicos/biosíntesis , Células Vegetales/metabolismo , Desarrollo de la Planta , Reacción en Cadena de la Polimerasa , Análisis Espectral , Transformación Genética
13.
Planta ; 247(4): 987-999, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29330614

RESUMEN

MAIN CONCLUSION: Ancymidol inhibits the incorporation of cellulose into cell walls of maize cell cultures in a gibberellin-independent manner, impairing cell growth; the reduction in the cellulose content is compensated with xylans. Ancymidol is a plant growth retardant which impairs gibberellin biosynthesis. It has been reported to inhibit cellulose synthesis by tobacco cells, based on its cell-malforming effects. To ascertain the putative role of ancymidol as a cellulose biosynthesis inhibitor, we conducted a biochemical study of its effect on cell growth and cell wall metabolism in maize cultured cells. Ancymidol concentrations ≤ 500 µM progressively reduced cell growth and induced globular cell shape without affecting cell viability. However, cell growth and viability were strongly reduced by ancymidol concentrations ≥ 1.5 mM. The I50 value for the effect of ancymidol on FW gain was 658 µM. A reversal of the inhibitory effects on cell growth was observed when 500 µM ancymidol-treated cultures were supplemented with 100 µM GA3. Ancymidol impaired the accumulation of cellulose in cell walls, as monitored by FTIR spectroscopy. Cells treated with 500 µM ancymidol showed a ~ 60% reduction in cellulose content, with no further change as the ancymidol concentration increased. Cellulose content was partially restored by 100 µM GA3. Radiolabeling experiments confirmed that ancymidol reduced the incorporation of [14C]glucose into α-cellulose and this reduction was not reverted by the simultaneous application of GA3. RT-PCR analysis indicated that the cellulose biosynthesis inhibition caused by ancymidol is not related to a downregulation of ZmCesA gene expression. Additionally, ancymidol treatment increased the incorporation of [3H]arabinose into a hemicellulose-enriched fraction, and up-regulated ZmIRX9 and ZmIRX10L gene expression, indicating an enhancement in the biosynthesis of arabinoxylans as a compensatory response to cellulose reduction.


Asunto(s)
Pared Celular/metabolismo , Reguladores del Crecimiento de las Plantas/farmacología , Pirimidinas/farmacología , Zea mays/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Celulosa/metabolismo , Relación Dosis-Respuesta a Droga , Giberelinas/farmacología , Zea mays/crecimiento & desarrollo , Zea mays/metabolismo
14.
Phys Chem Chem Phys ; 20(33): 21705-21715, 2018 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-30101953

RESUMEN

We performed a systematic study of electron-acceptor molecules in two closely related organometallic solids, namely, CuTCNQ and AgTCNQ. These studies were performed using both an experimental approach, via the use of electron spectroscopies (XPS and UPS), and a theoretical approach, via the use of ab initio DFT calculations. From these results, a complete description of the electronic structure of these molecular solid-films could be given, identifying the characteristic electronic and structural features of each part of the molecules and their contribution to the final electronic structure. Empty states were found close to the Fermi level in both solids. The presence of an electronic band close to the Fermi level is related to the magnetic behavior predicted for both MTCNQ solids for their isolated monolayers. However, the lower work function of the MTCNQ with respect to the metal substrate one implies that the MTCNQ film accepts electron from the metal substrate, thus fulfilling its Fermi level band. This occupied band explains the absence of shake-up features in the core level spectra in opposition to the TCNQ. The UPS experiments indicated that the MTCNQ film was doped by a small excess of metal from the substrate, shifting the electron Fermi level close to the MTCNQ conduction band. Thus, the MTCNQ film becomes an n-type semiconductor, opening up a very interesting field in the technological applications of this system.

15.
Phys Chem Chem Phys ; 20(15): 10450-10459, 2018 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-29617017

RESUMEN

In this article, we perform systematic research on the electronic structure of two closely related organic electron acceptor molecules (TCNQ and TCNE), which are of technological interest due to their outstanding electronic properties. These studies have been performed from the experimental point of view by the use electron spectroscopies (XPS and UPS) and supported theoretically by the use of ab-initio DFT calculations. The cross-check between both molecules allows us to identify the characteristic electronic features of each part of the molecules and their contribution to the final electronic structure. We can describe the nature of the band gap of these materials, and we relate this with the appearance of the shake-up features in the core level spectra. A band bending and energy gap reduction of the aforementioned electronic structure in contact with a metal surface are seen in the experimental results as well in the theoretical calculations. This behavior implies that the TCNQ thin film accepts electrons from the metal substrate becoming a Schottky n-junction.

16.
Eye Contact Lens ; 44 Suppl 2: S202-S209, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29420325

RESUMEN

PURPOSE: To analyze the variation in vertical coma and the rest of ocular aberrations before and after fitting prismatic soft contact lenses (PSCL). METHODS: Thirty-seven eyes of 20 healthy subjects (24.30±2.03 years) were evaluated to analyze the variation in ocular wavefront aberrations before and after fitting PSCL of different base-down prism values (1.0, 1.5, and 2.0 prism diopters [PD]), designed to study its influence in the compensation of vertical coma aberration. A Hartmann-Shack sensor with a wavelength of 780 nm was used, considering a pupil size of 3 mm. In addition, the influence of PSCL in visual function under photopic conditions in terms of high-contrast visual acuity and contrast sensitivity was evaluated. RESULTS: There was statistically significant differences (P<0.05) in ocular aberrations from first to seventh order after fitting PSCL, but only the differences in vertical tilt, horizontal tilt, defocus, vertical astigmatism, and vertical coma were clinically relevant (Strehl ratio <0.8). The mean of vertical coma (µm) was 0.022±0.030 for control, 0.045±0.064 for 1.0 PD (P=0.645), 0.048±0.053 for 1.5 PD (P=0.037), and 0.074±0.047 for 2.0 PD (P<0.001). The changes in visual function under photopic conditions were not clinically relevant. CONCLUSIONS: PSCL induce a magnitude of vertical coma aberration directly proportional to prism value without affecting the rest of ocular high-order aberrations.


Asunto(s)
Lentes de Contacto Hidrofílicos , Aberración de Frente de Onda Corneal/fisiopatología , Adulto , Análisis de Varianza , Astigmatismo/fisiopatología , Topografía de la Córnea , Estudios Transversales , Femenino , Humanos , Masculino , Estudios Prospectivos , Agudeza Visual/fisiología , Adulto Joven
17.
Am J Hum Biol ; 34(2): e23620, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34042248

RESUMEN

OBJECTIVES: International growth charts have been used in the past decades to identify atypical growth and diagnose the nutritional status of individuals. The aim of this study was to construct and compare growth patterns of normo-nourished children between 6-59 months from Afghanistan, Haiti, and the Democratic Republic of the Congo, to assess if it would be worth developing growth charts at a national level. METHODS: We used an international sample of 46 466 subjects (53.7% female; 46.3% male) from the aforementioned regions. To create the growth charts, we used different statistical methodologies: the Lambda-Mu-Sigma (LMS), LMSP, and LMST models, and regression models based on fractional polynomials. The LMSP models were the ones that fitted our data best and were therefore the ones used to make comparisons between countries using percentiles (3rd, 50th, and 97th). RESULTS: We found that Haitian children were both, taller and heavier than their Afghan and Congolese equals of the same ages. Moreover, differences were bigger in the highest percentiles (i.e., 97th percentile). These differences might be the result of the influence that genetics and diverse social and environmental contexts have on growth rates. CONCLUSIONS: Using the same international reference standards for all populations could result in the overestimation or underestimation of the proportion of malnourished children. In light of our results, we recommend the future development of national and regional growth charts to provide health workers with more precise tools to evaluate the nutritional status in the child population.


Asunto(s)
Desarrollo Infantil , Afganistán , Niño , Preescolar , Congo , Haití , Humanos , Lactante
18.
Eye Contact Lens ; 43(6): 346-351, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27203795

RESUMEN

OBJECTIVE: To evaluate the ocular surface temperature using an infrared thermography camera before and after wearing scleral lens in patients with keratoconus and correlate these results with the tear production and stability. METHODS: A pilot, experimental, short-term study has been performed. Twenty-six patients with keratoconus (36.95±8.95 years) participated voluntarily in the study. The sample was divided into two groups: patients with intrastromal corneal ring (KC-ICRS group) and patients without ICRS (KC group). Schirmer test, tear breakup time (TBUT), and ocular surface temperature in the conjunctiva, limbus, and cornea were evaluated before and after wearing a scleral lens. RESULTS: The patients wore the scleral lenses from 6 to 9 hours with average of 7.59±0.73 hours. No significant changes in Schirmer test and TBUT were found for both groups. No temperature differences were found between the KC-ICRS and the KC groups for all zones evaluated. There was a slight, but statistically significant, increase in the inferior cornea, temporal limbus, and nasal conjunctival temperature for KC-ICRS group and temporal limbus temperature decreasing for the KC group after wearing scleral lens (P<0.05). The conjunctiva and limbus temperature was statistically higher than the central cornea for both groups before and after scleral lenses wearing (P<0.05), but no difference in the peripheral cornea was found. No statistically significant differences in the central corneal temperature were found between the groups after scleral lens wearing (P>0.05). CONCLUSION: Scleral contact lens seems not to modify the ocular surface temperature despite the presence of the tear film stagnation under the lens.


Asunto(s)
Temperatura Corporal/fisiología , Conjuntiva/fisiología , Lentes de Contacto , Córnea/fisiología , Queratocono/terapia , Prótesis e Implantes , Esclerótica , Adulto , Femenino , Humanos , Queratocono/metabolismo , Limbo de la Córnea/fisiología , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Lágrimas/metabolismo , Termografía/métodos
19.
J Esthet Restor Dent ; 29(6): 396-402, 2017 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-28681488

RESUMEN

AIM: Dens evaginatus (DE) is described as an unusual dental malformation. Tooth structure variations attached to this anatomical disturbance complicates the performance of a conservative access cavity for a conventional root canal treatment. Author's purpose is to describe the treatment of a type V DE by using splits as guides to perform access cavity. CLINICAL CONSIDERATIONS: This clinical case shows a root canal treatment of a type V DE diagnosed by using a cone beam computed tomography (CBCT). Access cavity was planned through an osseointegrated implant planning software and guided by a stereolithographied split. After endodontic treatment, tooth was sculpted for placing a veneer, processed by a chair-side system in a single session. CONCLUSIONS: CBCT is an effective method for obtaining internal anatomical information of teeth with anatomical malformations. The osseointegrated implant planning software is an effective method for planning root canal treatment and designing stereolithograped splits (for performing minimally invasive access cavities). CLINICAL SIGNIFICANCE: Stereolithographed splints allow performing a guided and conservative access cavity of teeth affected by dental malformations whereas digital technology allows us to esthetically reconstruct a tooth in a single session.


Asunto(s)
Dens in Dente/cirugía , Diseño de Prótesis Dental/métodos , Tratamiento del Conducto Radicular/métodos , Férulas (Fijadores) , Adolescente , Diseño Asistido por Computadora , Tomografía Computarizada de Haz Cónico , Dens in Dente/diagnóstico por imagen , Femenino , Humanos , Incisivo/anomalías , Incisivo/diagnóstico por imagen , Maxilar , Impresión Tridimensional
20.
J Food Sci Technol ; 54(2): 422-429, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28242941

RESUMEN

The Baja California Peninsula in México has about 670 species of macroalgae along its coast. Species richness increases the probability of finding native macroalgae with potential as sources of bioactive compounds suitable for health, pharmacological, and cosmetic ingredients. To understand the biotechnological value of macroalgae from the peninsula, ethanol extracts from 17 macroalgae (four Chlorophyta, six Rhodophyta, seven Ochrophyta) were screened for antioxidant potential. To determine the antioxidant capacity of macroalgal extracts, 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power, and nitric oxide radical scavenging as well as total phenolic content (TPC) were measured. Extracts of the brown macroalgae were most active. Among these, Eisenia arborea, Padina concrecens, and Cystoseira osmundacea had the highest TPC and exhibited the strongest radical scavenging activities. Correlations were found between TPC macroalgal and scavenging capacity, indicating an important role of polyphenols as antioxidants. This suggests that some brown macroalgae from Baja California Peninsula may be a good source of natural bioactive compounds.

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