Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 294
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Opt Express ; 32(4): 6204-6214, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38439329

RESUMEN

We report laser frequency stabilization by the combination of modulation transfer spectroscopy and balanced detection of a relatively weak hyperfine transition of the R(158)25-0 line of molecular iodine (127I2), which is used as a new frequency reference for laser trapping and cooling of 174Yb on the 1S0 - 3P1 transition. The atomic cloud is characterized by time-of-flight measurements, and an on-resonance optical depth of up to 47 is obtained. We show laser noise reduction and characterize the short-term laser frequency instability by the Allan deviation of the laser fractional frequency. The minimum measured value is 3.9 ×10-13 at 0.17 s of averaging time.

2.
Nature ; 555(7695): 237-241, 2018 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-29516998

RESUMEN

Laboratory experiments and seismology data have created a clear theoretical picture of the most abundant minerals that comprise the deeper parts of the Earth's mantle. Discoveries of some of these minerals in 'super-deep' diamonds-formed between two hundred and about one thousand kilometres into the lower mantle-have confirmed part of this picture. A notable exception is the high-pressure perovskite-structured polymorph of calcium silicate (CaSiO3). This mineral-expected to be the fourth most abundant in the Earth-has not previously been found in nature. Being the dominant host for calcium and, owing to its accommodating crystal structure, the major sink for heat-producing elements (potassium, uranium and thorium) in the transition zone and lower mantle, it is critical to establish its presence. Here we report the discovery of the perovskite-structured polymorph of CaSiO3 in a diamond from South African Cullinan kimberlite. The mineral is intergrown with about six per cent calcium titanate (CaTiO3). The titanium-rich composition of this inclusion indicates a bulk composition consistent with derivation from basaltic oceanic crust subducted to pressures equivalent to those present at the depths of the uppermost lower mantle. The relatively 'heavy' carbon isotopic composition of the surrounding diamond, together with the pristine high-pressure CaSiO3 structure, provides evidence for the recycling of oceanic crust and surficial carbon to lower-mantle depths.

3.
Proc Natl Acad Sci U S A ; 118(11)2021 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-33707213

RESUMEN

Marine picocyanobacteria of the genus Prochlorococcus are the most abundant photosynthetic organisms in the modern ocean, where they exert a profound influence on elemental cycling and energy flow. The use of transmembrane chlorophyll complexes instead of phycobilisomes as light-harvesting antennae is considered a defining attribute of Prochlorococcus Its ecology and evolution are understood in terms of light, temperature, and nutrients. Here, we report single-cell genomic information on previously uncharacterized phylogenetic lineages of this genus from nutrient-rich anoxic waters of the eastern tropical North and South Pacific Ocean. The most basal lineages exhibit optical and genotypic properties of phycobilisome-containing cyanobacteria, indicating that the characteristic light-harvesting antenna of the group is not an ancestral attribute. Additionally, we found that all the indigenous lineages analyzed encode genes for pigment biosynthesis under oxygen-limited conditions, a trait shared with other freshwater and coastal marine cyanobacteria. Our findings thus suggest that Prochlorococcus diverged from other cyanobacteria under low-oxygen conditions before transitioning from phycobilisomes to transmembrane chlorophyll complexes and may have contributed to the oxidation of the ancient ocean.


Asunto(s)
Complejos de Proteína Captadores de Luz/genética , Oxígeno/análisis , Prochlorococcus/genética , Agua de Mar/microbiología , Clorofila/genética , Cianobacterias/clasificación , Cianobacterias/genética , Evolución Molecular , Genes Bacterianos/genética , Genoma Bacteriano/genética , Nutrientes/análisis , Océano Pacífico , Ficobilisomas/genética , Filogenia , Pigmentos Biológicos/genética , Prochlorococcus/clasificación , Agua de Mar/química
4.
Appl Environ Microbiol ; 89(5): e0215422, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-37133385

RESUMEN

Marine herbivorous fish that feed primarily on macroalgae, such as those from the genus Kyphosus, are essential for maintaining coral health and abundance on tropical reefs. Here, deep metagenomic sequencing and assembly of gut compartment-specific samples from three sympatric, macroalgivorous Hawaiian kyphosid species have been used to connect host gut microbial taxa with predicted protein functional capacities likely to contribute to efficient macroalgal digestion. Bacterial community compositions, algal dietary sources, and predicted enzyme functionalities were analyzed in parallel for 16 metagenomes spanning the mid- and hindgut digestive regions of wild-caught fishes. Gene colocalization patterns of expanded carbohydrate (CAZy) and sulfatase (SulfAtlas) digestive enzyme families on assembled contigs were used to identify likely polysaccharide utilization locus associations and to visualize potential cooperative networks of extracellularly exported proteins targeting complex sulfated polysaccharides. These insights into the gut microbiota of herbivorous marine fish and their functional capabilities improve our understanding of the enzymes and microorganisms involved in digesting complex macroalgal sulfated polysaccharides. IMPORTANCE This work connects specific uncultured bacterial taxa with distinct polysaccharide digestion capabilities lacking in their marine vertebrate hosts, providing fresh insights into poorly understood processes for deconstructing complex sulfated polysaccharides and potential evolutionary mechanisms for microbial acquisition of expanded macroalgal utilization gene functions. Several thousand new marine-specific candidate enzyme sequences for polysaccharide utilization have been identified. These data provide foundational resources for future investigations into suppression of coral reef macroalgal overgrowth, fish host physiology, the use of macroalgal feedstocks in terrestrial and aquaculture animal feeds, and the bioconversion of macroalgae biomass into value-added commercial fuel and chemical products.


Asunto(s)
Microbiota , Algas Marinas , Animales , Polisacáridos , Sulfatos , Arrecifes de Coral , Peces , Bacterias/genética
5.
Int J Legal Med ; 137(3): 851-861, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36719511

RESUMEN

Sexual dimorphism is the basis for sex estimation research in skeletal remains, helping the positive identification of individuals in forensic backgrounds. In this regard, it has been proved that the metrical analysis of the costal neck of the first four ribs in Spanish contemporary adult skeletons shows high sexual dimorphism, especially in the first rib. However, the validation of any method developed in identified skeletal collections must be compulsorily reproduced in other skeletonized sets to verify either its potential application in individuals from other locations, or the existence of possible biases associated with inter-population variation. Due to the geographical and socioeconomic proximity between Spain and Portugal, this paper aims to check the utility of the discriminant functions designed by Partido-Navadijo et al. (2021) in the two skeletal collections of the University of Coimbra (Portugal). Results show the utility of these discriminant functions in Portuguese population, with frequencies of cases correctly assigned reaching up to 93.6% in the Coimbra Identified Skeletal Collection (CISC); and up to 92.6% in the 21st Century Identified Skeletal Collection (CEI/XXI). However, two particularities between the Spanish and Portuguese osteological assemblages can be highlighted: the possible existence of secular changes in relation to the CISC collection (1904-1938); and a reversal in the degree of costal dimorphism, being the third and fourth ribs of the CEI/XXI collection more dimorphic than the first ones.


Asunto(s)
Antropología Forense , Determinación del Sexo por el Esqueleto , Humanos , Adulto , Portugal , Análisis Discriminante , Costillas/anatomía & histología , Etnicidad , Determinación del Sexo por el Esqueleto/métodos
6.
Nutr Metab Cardiovasc Dis ; 33(6): 1149-1157, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37095017

RESUMEN

BACKGROUND AND AIMS: Metabolically healthy (MHO) and unhealthy obesity (MUO) may be transient conditions. This study aimed to quantify and identify predictive factors of metabolic transitions in obesity, exploring influences of age and sex. METHODS AND RESULTS: We retrospectively evaluated adults with obesity who underwent routine health evaluation. In a cross-sectional analysis of 12,118 individuals (80% male, age 44.3 ± 9.9 years), 16.8% had MHO. In a longitudinal evaluation of 4483 participants, 45.2% of individuals with MHO at baseline had dysmetabolism after a median follow-up of 3.0 (IQR 1.8-5.2) years, whereas 13.3% MUO participants became metabolically healthy (MH). Development of hepatic steatosis (HS, ultrasound) was an independent predictor of MHO conversion to dysmetabolism (OR 2.36; 95% CI 1.43, 3.91; p < 0.001), while HS persistence was inversely associated with transition from MUO to MH status (OR 0.63; 95% CI 0.47, 0.83; p = 0.001). Female sex and older age were associated with a lower chance of MUO regression. A 5% increment in body mass index (BMI) over time increased the likelihood of metabolic deterioration by 33% (p = 0.002) in females and 16% (p = 0.018) in males with MHO. A 5% reduction in BMI was associated with a 39% and 66% higher chance of MUO resolution in females and males, respectively (both p < 0.001). CONCLUSION: The findings support a pathophysiological role of ectopic fat depots in metabolic transitions in obesity and identify female sex as an aggravating factor for adiposity-induced dysmetabolism, which has implications for personalized medicine.


Asunto(s)
Hígado Graso , Síndrome Metabólico , Obesidad Metabólica Benigna , Adulto , Humanos , Masculino , Femenino , Persona de Mediana Edad , Adiposidad , Estudios Retrospectivos , Estudios Transversales , Transición de la Salud , Obesidad/diagnóstico , Obesidad/epidemiología , Índice de Masa Corporal , Obesidad Metabólica Benigna/diagnóstico , Obesidad Metabólica Benigna/epidemiología , Factores de Riesgo , Fenotipo
7.
Phytochem Rev ; 21(6): 1887-1911, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35645656

RESUMEN

Propolis is a resinous natural product produced by honeybees using beeswax and plant exudates. The chemical composition of propolis is highly complex, and varies with region and season. This inherent chemical variability presents several challenges to its standardisation and quality control. The present review was aimed at highlighting marker compounds for different types of propolis, produced by the species Apis mellifera, from different geographical origins and that display different biological activities, and to discuss strategies for quality control. Over 800 compounds have been reported in the different propolises such as temperate, tropical, birch, Mediterranean, and Pacific propolis; these mainly include alcohols, acids and their esters, benzofuranes, benzopyranes, chalcones, flavonoids and their esters, glycosides (flavonoid and diterpene), glycerol and its esters, lignans, phenylpropanoids, steroids, terpenes and terpenoids. Among these, flavonoids (> 140), terpenes and terpenoids (> 160) were major components. A broad range of biological activities, such as anti-oxidant, antimicrobial, anti-inflammatory, immunomodulatory, and anticancer activities, have been ascribed to propolis constituents, as well as the potential of these compounds to be biomarkers. Several analytical techniques, including non-separation and separation methods have been described in the literature for the quality control assessment of propolis. Mass spectrometry coupled with separation methods, followed by chemometric analysis of the data, was found to be a valuable tool for the profiling and classification of propolis samples, including (bio)marker identification. Due to the rampant chemotypic variability, a multiple-marker assessment strategy considering geographical and biological activity marker(s) with chemometric analysis may be a promising approach for propolis quality assessment. Supplementary Information: The online version contains supplementary material available at 10.1007/s11101-022-09816-1.

8.
Cereb Cortex ; 31(1): 410-425, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-32887978

RESUMEN

The entorhinal cortex (EC) is a brain region that has been shown to be essential for memory functions and spatial navigation. However, detailed three-dimensional (3D) synaptic morphology analysis and identification of postsynaptic targets at the ultrastructural level have not been performed before in the human EC. In the present study, we used Focused Ion Beam/Scanning Electron Microscopy to perform a 3D analysis of the synapses in the neuropil of medial EC in layers II and III from human brain autopsies. Specifically, we studied synaptic structural parameters of 3561 synapses, which were fully reconstructed in 3D. We analyzed the synaptic density, 3D spatial distribution, and type (excitatory and inhibitory), as well as the shape and size of each synaptic junction. Moreover, the postsynaptic targets of synapses could be clearly determined. The present work constitutes a detailed description of the synaptic organization of the human EC, which is a necessary step to better understand the functional organization of this region in both health and disease.


Asunto(s)
Corteza Entorrinal/ultraestructura , Imagenología Tridimensional , Neurópilo/ultraestructura , Sinapsis/ultraestructura , Adulto , Anciano , Enfermedad de Alzheimer/patología , Humanos , Imagenología Tridimensional/métodos , Masculino , Persona de Mediana Edad , Neuronas/ultraestructura
9.
Graefes Arch Clin Exp Ophthalmol ; 260(4): 1183-1193, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34779906

RESUMEN

PURPOSE: This study aimed to assess the differences in blinking kinematics while reading on different digital displays and a control condition. METHODS: Thirty-two young healthy individuals were included in this prospective clinical study. The blinks of subjects were recorded for 150 s while reading on a laptop computer, tablet, e-reader, and smartphone and a control condition. Blinks were recorded using an eye-tracking device and were analyzed by means of image analysis to obtain a non-invasive detailed description of the blink movement. RESULTS: Blink rate decreased when reading on all displays compared to the control (p < 0.0005), although no differences were obtained amongst displays (p > 0.05). The percentage of incomplete blinks was higher with the computer compared to the control (p = 0.043), and lower with the smartphone compared to the rest of the conditions (p ≤ 0.015). Blink amplitude was smaller when reading from handheld devices compared to the control (p < 0.0005) and the computer (p ≤ 0.048). Closing and opening blink durations remained unvaried amongst conditions (p > 0.05), while opening and closing speeds were greater for the control and the computer compared to the handheld displays (p < 0.0005). Finally, contact and total blink durations were shorter during computer reading compared to the control (p = 0.004 and p = 0.017, respectively). CONCLUSION: Blinking kinematics vary considerably amongst displays and with respect to baseline, with these differences being probably attributed to differences in the way the displays are set up and the cognitive demand of the task.


Asunto(s)
Parpadeo , Computadores , Fenómenos Biomecánicos , Humanos , Estudios Prospectivos , Lectura
10.
Phytochem Anal ; 33(8): 1177-1189, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35949064

RESUMEN

INTRODUCTION: Many species within Combretaceae are traditionally used for the treatment of bacterial infections. The similarity in chemistry and antimicrobial activities within the family pose a challenge in selecting suitable species for herbal drug development. OBJECTIVE: This study aimed at rapidly identifying antimicrobial compounds using bioautography-guided high-performance thin-layer chromatography coupled with mass spectrometry (HPTLC-MS). METHODS: Hierarchical cluster analysis of ultra-performance liquid chromatography-mass spectrometry data from the methanol extracts of 77 samples, representing four genera within Combretaceae, was carried out. Based on groupings on the dendrogram, 15 samples were selected for bioautography analysis against four pathogens (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhimurium). Active compounds were identified using HPTLC-MS analysis of bands corresponding to the inhibition zones. RESULTS: Bioautography revealed 15 inhibition zones against the four pathogens, with the most prominent present for Combretum imberbe. Analysis of the active bands, using HPTLC-MS indicated that flavonoids, triterpenoids and combretastatin B5 contributed to the antibacterial activity. The compounds corresponding to molecular ions m/z 471 (Combretum imberbe) and 499 (Combretum elaeagnoides) inhibited all four pathogens, and were identified as imberbic acid and jessic acid, respectively. Chemotaxonomic analysis indicated that arjunic acid, ursolic acid and an unidentified triterpenoid (m/z 471) were ubiquitous in the Combretaceae species and could be responsible for their antibacterial activities. CONCLUSION: Application of HPTLC-MS enabled the rapid screening of extracts to identify active compounds within taxonomically related species. This approach allows for greater efficiency in the natural product research workflow to identify bioactive compounds in crude extracts.


Asunto(s)
Antiinfecciosos , Combretaceae , Cromatografía en Capa Delgada/métodos , Sudáfrica , Espectrometría de Masas/métodos , Antibacterianos/farmacología , Antibacterianos/química , Antiinfecciosos/farmacología , Escherichia coli , Extractos Vegetales/farmacología , Extractos Vegetales/química
11.
Molecules ; 27(13)2022 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-35807440

RESUMEN

Culinary herbs and spices are known to be good sources of natural antioxidants. Although the antioxidant effects of individual culinary herbs and spices are widely reported, little is known about their effects when used in combination. The current study was therefore undertaken to compare the antioxidant effects of crude extracts and essential oils of some common culinary herbs and spices in various combinations. The antioxidant interactions of 1:1 combinations of the most active individual extracts and essential oils were investigated as well as the optimization of various ratios using the design of experiments (DoE) approach. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays were used to determine the antioxidant activity, and MODDE 9.1® software (Umetrics AB, Umea, Sweden) was used to determine the DoE. The results revealed synergism for the following combinations: Mentha piperita with Thymus vulgaris methanol extract (ΣFIC = 0.32 and ΣFIC = 0.15 using the DPPH and FRAP assays, respectively); Rosmarinus officinalis with Syzygium aromaticum methanol extract (ΣFIC = 0.47 using the FRAP assay); T. vulgaris with Zingiber officinalis methanol extracts (ΣFIC = 0.19 using the ABTS assay); and R. officinalis with Z. officinalis dichloromethane extract (ΣFIC = 0.22 using the ABTS assay). The DoE produced a statistically significant (R2 = 0.905 and Q2 = 0.710) model that was able to predict extract combinations with high antioxidant activities, as validated experimentally. The antioxidant activities of the crude extracts from a selection of culinary herbs and spices were improved when in combination, hence creating an innovative opportunity for the future development of supplements for optimum health.


Asunto(s)
Antioxidantes , Aceites Volátiles , Antioxidantes/farmacología , Metanol , Aceites Volátiles/farmacología , Extractos Vegetales/farmacología , Proyectos de Investigación
12.
Emerg Infect Dis ; 27(9): 2409-2420, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34424181

RESUMEN

In Ceará, Brazil, seasonal influenza transmission begins before national annual vaccination campaigns commence. To assess the perinatal consequences of this misalignment, we tracked severe acute respiratory infection (SARI), influenza, and influenza immunizations during 2013-2018. Among 3,297 SARI cases, 145 (4.4%) occurred in pregnant women. Statewide vaccination coverage was >80%; however, national vaccination campaigns began during or after peak influenza season. Thirty to forty weeks after peak influenza season, birthweights decreased by 40 g, and rates of prematurity increased from 10.7% to 15.5%. We identified 61 children born to mothers with SARI during pregnancy; they weighed 10% less at birth and were more likely to be premature than 122 newborn controls. Mistiming of influenza vaccination campaigns adversely effects perinatal outcomes in Ceará. Because Ceará is the presumptive starting point for north-to-south seasonal influenza transmission in Brazil, earlier national immunization campaigns would provide greater protection for pregnant women and their fetuses in Ceará and beyond.


Asunto(s)
Gripe Humana , Complicaciones Infecciosas del Embarazo , Brasil/epidemiología , Niño , Femenino , Humanos , Recién Nacido , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Parto , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/prevención & control , Vacunación
13.
Calcif Tissue Int ; 109(2): 231-240, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33792736

RESUMEN

Pathophysiological conditions can modify the skeletal chemical concentration. This study analyzes the elemental composition in two anatomical regions from dry femoral bone using a portable X-Ray Fluorescence (pXRF) and evaluates its impact in the bone mineral density (BMD). The left femora of 97 female skeletons (21-95 years old individuals) from the Coimbra Identified Skeletal Collection were studied. Diagenetic biases were discarded at the outset and BMD was determined with Dual-energy X-ray absorptiometry. Chemical measurements were performed at the midpoint of the femoral neck and at the midshaft using a pXRF device, and comparisons were made considering the age and the BMD values. Only elements with a Technical Measurement Error ≤ 5% were selected: P, S, Ca, Fe, Zn, As, Sr, Pb and the Ca/P ratio. Statistically significant differences were found between regions, with higher concentrations of P, Ca, Zn and S at the midshaft, and the Ca/P ratio at the femoral neck. The concentration of P is higher in individuals < 50 years, while S and Ca/P ratio increase in individuals ≥ 50 years. The decrease of P with age can be simultaneously related to the decline of its concentration in osteoporosis. Decreased BMD is also associated with higher levels of S and Pb. Osteoporosis enhances the absorption of osteolytic elements in specific locations. This fast and non-destructive technique has proved effective for the comprehension of chemical changes related to bone mass loss. This study highlights the potential of identified skeletal collections to improve the knowledge about bone fragility.


Asunto(s)
Osteoporosis , Absorciometría de Fotón , Adulto , Anciano , Anciano de 80 o más Años , Densidad Ósea , Femenino , Cuello Femoral/diagnóstico por imagen , Humanos , Persona de Mediana Edad , Rayos X , Adulto Joven
14.
Int J Legal Med ; 135(3): 993-1003, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32990776

RESUMEN

Non-adult sex estimation is an active field of forensic inquiry as morphological variations between males and females are subtle, but observable, even from intrauterine development. The objectives of this study are threefold: to test the validity of the auricular surface method for sex estimation (Int J Osteoarchaeol 27:898-911, 2017) in fetuses and children under the age of 5 years old; to evaluate if health conditions, reported as the cause of death, influence its accuracy; and to detect possible secular trends in sexual dimorphism. One-hundred and ninety-seven skeletal individuals from the Lisbon and Granada Identified Collections were studied. Individuals were divided according to the hormonal peaks (< 0, 0-2, < 2, and 2.1-5 years old), cause, and year of death (before and after 1960). As in previous studies, two ratios (FI/CF and DE/AD) and two qualitative variables (OM and MRS) showed the highest frequencies of correct estimation (0.81-0.86). The correct sex allocations increased when the discriminant function (0.85) and logistic regression (0.86) were applied. Males of the age groups < 0 and 2.1-5 years were all correctly sexed by both formulae, and the same was observed for the female probabilities of adequate allocation. The cause and year of death were identified as variables without statistical significance. It is proposed that this method can be incorporated with confidence into the multifactorial laboratory protocols for non-adult sex estimation from skeletal remains.


Asunto(s)
Ilion/anatomía & histología , Caracteres Sexuales , Determinación del Sexo por el Esqueleto/métodos , Restos Mortales , Desarrollo Infantil/fisiología , Preescolar , Análisis por Conglomerados , Análisis Discriminante , Femenino , Desarrollo Fetal/fisiología , Humanos , Lactante , Recién Nacido , Modelos Logísticos , Masculino , Portugal , Probabilidad , Reproducibilidad de los Resultados , España
15.
J Card Surg ; 36(12): 4722-4731, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34580899

RESUMEN

OBJECTIVES: To determine the outcomes of bioprosthetic valve fracture (BVF) in valve-in-valve transcatheter aortic valve implantation (ViV-TAVI) for patients with structural valve degeneration (SVD) of bioprosthetic surgical valves (BSV) implanted during surgical aortic valve replacement (SAVR). METHODS: A systematic review was conducted including studies published by May 2021. The primary endpoints of the study were 30-day mortality, annular rupture, stroke, paravalvular leak, pacemaker implantation, and coronary obstruction. The secondary endpoints were mean valve gradients (mmHg) and aortic valve area (AVA-cm2 ). A meta-analysis was conducted using the software R, version 3.6.3 (R Foundation for Statistical Computing). RESULTS: Four studies including 242 patients met our eligibility criteria. The overall proportions for 30-day mortality, annular rupture, stroke, paravalvular leak, pacemaker implantation and coronary obstruction were 2.1%, <1.0%, <1.5%, <1.0%, <1.0%, and <1.5%, respectively. After ViV-TAVI with BVF, the difference in means for mean valve gradients showed a significant reduction (random-effects model: -26.7; -28.8 to -24.7; p < .001), whereas the difference in means for AVA showed a significant increase (random-effects model: 0.55 cm2 ; 0.13-0.97; p = .029). Despite the improvement in AVA means, these remain too low after the procedure highly likely due to the small size of the bioprosthetic valves implanted during the index SAVR. CONCLUSION: ViV-TAVI with BVF has proven to be a promising option but data are still too scarce to enable us to draw definitive conclusions. Despite the decrease in gradients, postprocedural AVA remains worrisome. Studies with better designs and larger sample sizes are needed to advance this treatment option.


Asunto(s)
Estenosis de la Válvula Aórtica , Bioprótesis , Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/cirugía , Humanos , Factores de Riesgo , Resultado del Tratamiento
16.
J ECT ; 37(1): 58-63, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33009217

RESUMEN

BACKGROUND: Given the limited therapeutic options for Prader-Willi syndrome (PWS), we conducted an open-label clinical trial to evaluate the effects of transcranial direct current stimulation (tDCS) for hyperphagia, food craving, and aberrant behaviors on this population. METHODS: Twelve subjects with PWS (11-35 years old) were included. The subjects underwent 10 daily 20-minute sessions of tDCS in 2 weeks. The anode was positioned over the left dorsolateral prefrontal cortex, and the cathode over the contralateral region. RESULTS: We observed amelioration of hyperphagic and food craving symptoms (P < 0.05), as well as amelioration of behavioral symptoms measured with the Aberrant Behavior Checklist (P < 0.05). DISCUSSION: To our knowledge, this is the first proof-of-concept trial to report the positive effects of increasing excitability of the left dorsolateral prefrontal cortex, using tDCS, for the behavioral, hyperphagia, and food craving symptoms in PWS, which is a low-cost, well-studied, safe alternative for brain stimulation.


Asunto(s)
Síndrome de Prader-Willi/terapia , Estimulación Transcraneal de Corriente Directa , Adolescente , Adulto , Anciano , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad
17.
Molecules ; 26(2)2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33467662

RESUMEN

Terminalia sericea is used throughout Africa for the treatment of a variety of conditions and has been identified as a potential commercial plant. The study was aimed at establishing a high-performance thin layer chromatography (HPTLC) chemical fingerprint for T. sericea root bark as a reference for quality control and exploring chemical variation within the species using HPTLC metabo3lomics. Forty-two root bark samples were collected from ten populations in South Africa and extracted with dichloromethane: methanol (1:1). An HPTLC method was optimized to resolve the major compounds from other sample components. Dichloromethane: ethyl acetate: methanol: formic acid (90:10:30:1) was used as the developing solvent and the plates were visualized using 10% sulfuric acid in methanol as derivatizing agent. The concentrations of three major bioactive compounds, sericic acid, sericoside and resveratrol-3-O-ß-rutinoside, in the extracts were determined using a validated ultra-performance liquid chromatography-photodiode array (UPLC-PDA) detection method. The rTLC software (written in the R-programming language) was used to select the most informative retardation factor (Rf) ranges from the images of the analysed sample extracts. Further chemometric models, including principal component analysis (PCA) and hierarchical cluster analysis (HCA), were constructed using the web-based high throughput metabolomic software. The rTLC chemometric models were compared with the models previously obtained from ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). A characteristic fingerprint containing clear bands for the three bioactive compounds was established. All three bioactive compounds were present in all the samples, although their corresponding band intensities varied. The intensities correlated with the UPLC-PDA results, in that samples containing a high concentration of a particular compound, displayed a more intense band. Chemometric analysis using HCA revealed two chemotypes, and the subsequent construction of a loadings plot indicated that sericic acid and sericoside were responsible for the chemotypic variation; with sericoside concentrated in Chemotype 1, while sericic acid was more abundant in Chemotype 2. A characteristic chemical fingerprint with clearly distinguishable features was established for T. sericea root bark that can be used for species authentication, and to select samples with high concentrations of a particular marker compound(s). Different chemotypes, potentially differing in their therapeutic potency towards a particular target, could be distinguished. The models revealed the three analytes as biomarkers, corresponding to results reported for UPLC-MS profiling and thereby indicating that HPTLC is a suitable technique for the quality control of T. sericea root bark.


Asunto(s)
Fitoquímicos/análisis , Fitoquímicos/metabolismo , Terminalia/química , Terminalia/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Cromatografía en Capa Delgada/métodos , Metaboloma , Fitoquímicos/aislamiento & purificación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/metabolismo , Control de Calidad , Sudáfrica , Terminalia/clasificación
18.
J Obstet Gynaecol ; 41(7): 1102-1106, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33432854

RESUMEN

Hysterectomy is the most common major gynaecological surgery. Due to its high volume, the analysis of its results is relevant. The objective of this study was to describe intraoperative complications and reoperations, for both benign and malignant causes, using the Clavien-Dindo classification (approved by local ethics committee, number 100220). Between 2000 and 2019, 5926 elective hysterectomies were performed, of which 90.2% were for benign aetiology and 9.8% for malignant causes. The abdominal route was 52.7%, vaginal 40.1% and laparoscopic 7.2%. Intraoperative complications and reoperations (grade III Clavien-Dindo) were 4% and 2.1%, respectively. Oncological surgery had significantly more intraoperative complications (10% vs. 3.4%) and reoperations (3.6% vs. 1.9%) than benign procedures. Noteworthy, intraoperative complications required a new operation in only 3.4% for malignant and 2.8% for benign surgery. Our data showed the relevance of detecting and rectifying intraoperative complications during surgery, which consequently leads to a lower reoperation rate, minimising postoperative morbidity and mortality for patients.Impact StatementWhat is already known on this subject? The surgical complications of hysterectomy, both intraoperative and postoperative, are extensively described. However, this information is not well systematised, in which elective and emergency surgery are mixed. In addition to the above, there are few documents comparing the results of hysterectomies due to benign versus malignant causes.What the results of this study add? Using the Clavien-Dindo classification, this study adds an organised description of intraoperative complications and reoperations of hysterectomy in the context of elective surgery. In addition, it provides information on the comparison between surgery for benign versus malignant causes, as well as information on intraoperative complications requiring a new operation.What the implications are of these findings for clinical practice and/or further research? These findings provide clear and orderly data about the risks of elective hysterectomy and showed the relevance of detecting and rectifying intraoperative complications during the procedure. This is useful for specialists to preoperatively identify the risks for each hysterectomy group and provide their patients with more detailed information during informed consent.


Asunto(s)
Enfermedades de los Genitales Femeninos/cirugía , Histerectomía/efectos adversos , Complicaciones Intraoperatorias/clasificación , Complicaciones Posoperatorias/clasificación , Reoperación/clasificación , Adulto , Chile , Femenino , Humanos , Histerectomía/métodos , Complicaciones Intraoperatorias/etiología , Laparoscopía/efectos adversos , Laparoscopía/métodos , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Sistema de Registros , Estudios Retrospectivos , Vagina/cirugía
19.
Phys Rev Lett ; 124(11): 110605, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-32242711

RESUMEN

We give rigorous analytical results on the temporal behavior of two-point correlation functions-also known as dynamical response functions or Green's functions-in closed many-body quantum systems. We show that in a large class of translation-invariant models the correlation functions factorize at late times ⟨A(t)B⟩_{ß}→⟨A⟩_{ß}⟨B⟩_{ß}, thus proving that dissipation emerges out of the unitary dynamics of the system. We also show that for systems with a generic spectrum the fluctuations around this late-time value are bounded by the purity of the thermal ensemble, which generally decays exponentially with system size. For autocorrelation functions we provide an upper bound on the timescale at which they reach the factorized late time value. Remarkably, this bound is only a function of local expectation values and does not increase with system size. We give numerical examples that show that this bound is a good estimate in nonintegrable models, and argue that the timescale that appears can be understood in terms of an emergent fluctuation-dissipation theorem. Our study extends to further classes of two point functions such as the symmetrized ones and the Kubo function that appears in linear response theory, for which we give analogous results.

20.
Curr Atheroscler Rep ; 22(2): 9, 2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-32034516

RESUMEN

PURPOSE OF REVIEW: This review summarizes the pathophysiology of mitral annular calcification (MAC) with recent findings and current strategies for diagnosis and treatment. RECENT FINDINGS: Major factors in MAC development seem to be shear stress of the flow past the mitral valve, local inflammation, and dysregulation in regulators of mineral metabolism. MAC itself poses daunting technical challenges. Implanting a valve on top of the calcium bar might lead to paravalvular leak (PVL) that is less likely to heal. Annular decalcification allows for better valve seating and potentially better healing and less PVL. This, however, comes with the risk for catastrophic atrioventricular groove disruption. MAC can be sharply dissected with the scalpel; the annulus can be reconstructed with the autologous pericardium. Transcatheter mitral valve replacement is a promising approach in the treatment of patients who are deemed high-risk surgical candidates with severe MAC. MAC is a multifactorial disease that has some commonalities with atherosclerosis, mainly regarding lipid accumulation and calcium deposition. It is of great clinical importance, being a risk marker of cardiovascular events (including sudden death) and, with its progression, can have a negative impact on patients' lives.


Asunto(s)
Aterosclerosis/fisiopatología , Enfermedades de las Válvulas Cardíacas/diagnóstico , Enfermedades de las Válvulas Cardíacas/fisiopatología , Válvula Mitral/fisiopatología , Calcificación Vascular/diagnóstico , Calcificación Vascular/fisiopatología , Anciano , Calcio/sangre , Femenino , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Humanos , Masculino , Válvula Mitral/cirugía , Anuloplastia de la Válvula Mitral/efectos adversos , Factores de Riesgo , Calcificación Vascular/cirugía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA