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1.
Am J Gastroenterol ; 119(1): 87-96, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37734342

RESUMEN

INTRODUCTION: The aim of this study was to compare the effectiveness of glucagon vs placebo in resolving esophageal foreign body impaction (EFBI), as well as the length of the procedure and adverse events. METHODS: This was a multicenter, randomized, double-blind trial involving consecutive patients diagnosed with alimentary EFBI. Participants were randomized to receive either 1 mg of intravenous glucagon or placebo. All patients underwent upper endoscopy, and adverse events were assessed through a protocolized telephonic interview 7 days later. RESULTS: The study included 72 subjects in the glucagon group and 68 in the placebo group. The foreign body was not identified in 23.6% of subjects in the glucagon group and 20.6% of subjects in the placebo group (difference 3%, 95% confidence interval -10.7% to 16.8%, P = 0.67). The median time required to remove the foreign body was similar in both groups 4 minutes (range 2-10) in the glucagon group and 3.5 minutes (range 2-7) in the placebo group (difference 0.5 minutes, 95% confidence interval -1.3 to 2.3; P = 0.59). The most common adverse event reported in both groups was mild pharyngeal pain. DISCUSSION: Glucagon is no more effective than placebo in resolving EFBI or shortening the time required to remove the foreign body (EUDRA-CT number 2019-004920-40).


Asunto(s)
Cuerpos Extraños , Glucagón , Humanos , Glucagón/uso terapéutico , Esófago , Dolor/tratamiento farmacológico , Endoscopía , Método Doble Ciego
2.
J Neurooncol ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39044115

RESUMEN

PURPOSE: The objective of this prospective, single-centre case series was to investigate feasibility, clinical outcomes, and neural correlates of non-invasive Neuromodulation-Induced Cortical Prehabilitation (NICP) before brain tumor surgery. Previous studies have shown that gross total resection is paramount to increase life expectancy but is counterbalanced by the need of preserving critical functional areas. NICP aims at expanding functional margins for extensive tumor resection without functional sequelae. Invasive NICP (intracranial neuromodulation) was effective but characterized by elevated costs and high rate of adverse events. Non-invasive NICP (transcranial neuromodulation) may represent a more feasible alternative. Nonetheless, up to this point, non-invasive NICP has been examined in only two case reports, yielding inconclusive findings. METHODS: Treatment sessions consisted of non-invasive neuromodulation, to transiently deactivate critical areas adjacent to the lesion, coupled with intensive functional training, to activate alternative nodes within the same functional network. Patients were evaluated pre-NICP, post-NICP, and at follow-up post-surgery. RESULTS: Ten patients performed the intervention. Feasibility criteria were met (retention, adherence, safety, and patient's satisfaction). Clinical outcomes showed overall stability and improvements in motor and executive function from pre- to post-NICP, and at follow-up. Relevant plasticity changes (increase in the distance between tumor and critical area) were observed when the neuromodulation target was guided by functional neuroimaging data. CONCLUSION: This is the first case series demonstrating feasibility of non-invasive NICP. Neural correlates indicate that neuroimaging-guided target selection may represent a valid strategy to leverage neuroplastic changes before neurosurgery. Further investigations are needed to confirm such preliminary findings.

3.
Gastroenterol Hepatol ; : 502218, 2024 Jun 08.
Artículo en Inglés, Español | MEDLINE | ID: mdl-38857753

RESUMEN

INTRODUCTION: Self-expandable metallic stents (SEMS) have been widely placed for unresectable distal malignant biliary obstruction (UDMBO). However, the dysfunction rate is 19-40% and its treatment is controversial. We aimed asses the efficacy and safety of a secondary biliary stents (uncovered (UC) versus fully-covered (FC) stent) for the management of occluded SEMS. PATIENTS AND METHODS: Between 2015 and June 2023, 41 patients with UDMBO underwent secondary biliary stent placement as "stent-in-stent" (20 FCSEMS and 21 UCSEMS). The primary outcomes were technical and clinical success of SEMS placement. Secondary outcomes included adverse events (AEs), patency and survival. Patients were prospectively followed until death or loss of follow-up. RESULTS: Technical (100% vs 85.5%) and clinical (100% vs 95.2%) success rates were similar in FCSEMS and UCSEMS groups. The median follow-up period was 510 days (range 290-630). The median duration of stent patency of FCSEMS (220 days, IQR 137.5-442.5) was longer than UCSEMS (150 days, IQR 110-362.5) (P=0.395), although stent dysfunction within 6 months was not different between groups. Multivariate analysis indicated that sex (HR=0.909, 0.852-0.970), antitumor treatment (HR=0.248, 0.032-0.441), stent patency (HR=0.992, 0.986-0.998) and clinical success (HR=0.133, 0.026-0.690) were significant factors for overall survival. There were no remarkable differences in AEs. CONCLUSIONS: The placement of additional biliary stent using the stent-in-stent method is an effective and safe rescue treatment for patients with UDMBO and occluded stent. In addition, the use of FCSEMS compared UCSEMS has unclear benefits regarding stent patency and overall survival.

4.
Small ; 19(40): e2302355, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37282744

RESUMEN

By preparing colloidal crystals with random missing scatterers, crystals are created where disorder is embodied as vacancies in an otherwise perfect lattice. In this special system, there is a critical defect concentration where light propagation undergoes a transition from an all but perfect reflector (for the spectral range defined by the Bragg condition), to a metamaterial exhibiting an enhanced transmission phenomenon. It is shown that this behavior can be phenomenologically described in terms of Fano-like resonances. The results show that the Fano's parameter q experiences a sign change signaling the transition from a perfect crystal exhibiting a reflectance Bragg peak, through a state where background scattering is maximum and Bragg reflectance reaches a minimum to a point where the system reenters a low scattering state recovering ordinary Bragg diffraction. A simple dipolar model considering the correlation between scatterers and vacancies is proposed and the reported evolution of the Fano-like scattering is explained in terms of the emerging covariance between the optical paths and polarizabilities and the effect of field enhancement in photonic crystal (PhC) defects.

5.
Mol Psychiatry ; 27(4): 2114-2125, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35136228

RESUMEN

Small average differences in the left-right asymmetry of cerebral cortical thickness have been reported in individuals with autism spectrum disorder (ASD) compared to typically developing controls, affecting widespread cortical regions. The possible impacts of these regional alterations in terms of structural network effects have not previously been characterized. Inter-regional morphological covariance analysis can capture network connectivity between different cortical areas at the macroscale level. Here, we used cortical thickness data from 1455 individuals with ASD and 1560 controls, across 43 independent datasets of the ENIGMA consortium's ASD Working Group, to assess hemispheric asymmetries of intra-individual structural covariance networks, using graph theory-based topological metrics. Compared with typical features of small-world architecture in controls, the ASD sample showed significantly altered average asymmetry of networks involving the fusiform, rostral middle frontal, and medial orbitofrontal cortex, involving higher randomization of the corresponding right-hemispheric networks in ASD. A network involving the superior frontal cortex showed decreased right-hemisphere randomization. Based on comparisons with meta-analyzed functional neuroimaging data, the altered connectivity asymmetry particularly affected networks that subserve executive functions, language-related and sensorimotor processes. These findings provide a network-level characterization of altered left-right brain asymmetry in ASD, based on a large combined sample. Altered asymmetrical brain development in ASD may be partly propagated among spatially distant regions through structural connectivity.


Asunto(s)
Trastorno del Espectro Autista , Encéfalo , Mapeo Encefálico , Corteza Cerebral/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , Vías Nerviosas
6.
Brain ; 145(11): 3859-3871, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-35953082

RESUMEN

One outstanding challenge for machine learning in diagnostic biomedical imaging is algorithm interpretability. A key application is the identification of subtle epileptogenic focal cortical dysplasias (FCDs) from structural MRI. FCDs are difficult to visualize on structural MRI but are often amenable to surgical resection. We aimed to develop an open-source, interpretable, surface-based machine-learning algorithm to automatically identify FCDs on heterogeneous structural MRI data from epilepsy surgery centres worldwide. The Multi-centre Epilepsy Lesion Detection (MELD) Project collated and harmonized a retrospective MRI cohort of 1015 participants, 618 patients with focal FCD-related epilepsy and 397 controls, from 22 epilepsy centres worldwide. We created a neural network for FCD detection based on 33 surface-based features. The network was trained and cross-validated on 50% of the total cohort and tested on the remaining 50% as well as on 2 independent test sites. Multidimensional feature analysis and integrated gradient saliencies were used to interrogate network performance. Our pipeline outputs individual patient reports, which identify the location of predicted lesions, alongside their imaging features and relative saliency to the classifier. On a restricted 'gold-standard' subcohort of seizure-free patients with FCD type IIB who had T1 and fluid-attenuated inversion recovery MRI data, the MELD FCD surface-based algorithm had a sensitivity of 85%. Across the entire withheld test cohort the sensitivity was 59% and specificity was 54%. After including a border zone around lesions, to account for uncertainty around the borders of manually delineated lesion masks, the sensitivity was 67%. This multicentre, multinational study with open access protocols and code has developed a robust and interpretable machine-learning algorithm for automated detection of focal cortical dysplasias, giving physicians greater confidence in the identification of subtle MRI lesions in individuals with epilepsy.


Asunto(s)
Epilepsias Parciales , Epilepsia , Malformaciones del Desarrollo Cortical , Humanos , Estudios Retrospectivos , Malformaciones del Desarrollo Cortical/complicaciones , Malformaciones del Desarrollo Cortical/diagnóstico por imagen , Epilepsia/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Aprendizaje Automático , Epilepsias Parciales/diagnóstico por imagen
7.
Eur Child Adolesc Psychiatry ; 32(3): 513-526, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34604924

RESUMEN

Anorexia nervosa (AN) typically emerges in adolescence. The cortico-striatal system (CSTS) and the default mode network (DMN) are brain circuits with a crucial development during this period. These circuits underlie cognitive functions that are impaired in AN, such as cognitive flexibility and inhibition, among others. Little is known about their involvement in adolescent AN and how weight and symptom improvement might modulate potential alterations in these circuits. Forty-seven adolescent females (30 AN, 17 healthy control) were clinically/neuropsychologically evaluated and scanned during a 3T-MRI resting-state session on two occasions, before and after a 6-month multidisciplinary treatment of the AN patients. Baseline and baseline-to-follow-up between-group differences in CSTS and DMN resting-state connectivity were evaluated, as well as their association with clinical/neuropsychological variables. Increased connectivity between the left dorsal putamen and the left precuneus was found in AN at baseline. At follow-up, body mass index and clinical symptoms had improved in the AN group. An interaction effect was found in the connectivity between the right dorsal caudate to right mid-anterior insular cortex, with lower baseline AN connectivity that improved at follow-up; this improvement was weakly associated with changes in neuropsychological (Stroop test) performance. These results support the presence of CSTS connectivity alterations in adolescents with AN, which improve with weight and symptom improvement. In addition, at the level of caudate-insula connectivity, they might be associated with inhibitory processing performance. Alterations in CSTS pathways might be involved in AN from the early stages of the disorder.


Asunto(s)
Anorexia Nerviosa , Mapeo Encefálico , Femenino , Humanos , Adolescente , Estudios Longitudinales , Anorexia Nerviosa/diagnóstico por imagen , Anorexia Nerviosa/terapia , Red en Modo Predeterminado , Vías Nerviosas/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos
8.
Epilepsia ; 63(1): 61-74, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34845719

RESUMEN

OBJECTIVE: Drug-resistant focal epilepsy is often caused by focal cortical dysplasias (FCDs). The distribution of these lesions across the cerebral cortex and the impact of lesion location on clinical presentation and surgical outcome are largely unknown. We created a neuroimaging cohort of patients with individually mapped FCDs to determine factors associated with lesion location and predictors of postsurgical outcome. METHODS: The MELD (Multi-centre Epilepsy Lesion Detection) project collated a retrospective cohort of 580 patients with epilepsy attributed to FCD from 20 epilepsy centers worldwide. Magnetic resonance imaging-based maps of individual FCDs with accompanying demographic, clinical, and surgical information were collected. We mapped the distribution of FCDs, examined for associations between clinical factors and lesion location, and developed a predictive model of postsurgical seizure freedom. RESULTS: FCDs were nonuniformly distributed, concentrating in the superior frontal sulcus, frontal pole, and temporal pole. Epilepsy onset was typically before the age of 10 years. Earlier epilepsy onset was associated with lesions in primary sensory areas, whereas later epilepsy onset was associated with lesions in association cortices. Lesions in temporal and occipital lobes tended to be larger than frontal lobe lesions. Seizure freedom rates varied with FCD location, from around 30% in visual, motor, and premotor areas to 75% in superior temporal and frontal gyri. The predictive model of postsurgical seizure freedom had a positive predictive value of 70% and negative predictive value of 61%. SIGNIFICANCE: FCD location is an important determinant of its size, the age at epilepsy onset, and the likelihood of seizure freedom postsurgery. Our atlas of lesion locations can be used to guide the radiological search for subtle lesions in individual patients. Our atlas of regional seizure freedom rates and associated predictive model can be used to estimate individual likelihoods of postsurgical seizure freedom. Data-driven atlases and predictive models are essential for evidence-based, precision medicine and risk counseling in epilepsy.


Asunto(s)
Epilepsia Refractaria , Epilepsia , Malformaciones del Desarrollo Cortical , Niño , Epilepsia Refractaria/complicaciones , Epilepsia Refractaria/diagnóstico por imagen , Epilepsia Refractaria/cirugía , Epilepsia/diagnóstico por imagen , Epilepsia/etiología , Epilepsia/cirugía , Libertad , Humanos , Imagen por Resonancia Magnética , Malformaciones del Desarrollo Cortical/complicaciones , Malformaciones del Desarrollo Cortical/diagnóstico por imagen , Malformaciones del Desarrollo Cortical/cirugía , Estudios Retrospectivos , Convulsiones/diagnóstico por imagen , Convulsiones/etiología , Convulsiones/cirugía , Resultado del Tratamiento
9.
Eur Radiol ; 32(7): 4510-4520, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35182205

RESUMEN

OBJECTIVES: After an acute ischemic stroke, patients with a large CT perfusion (CTP) predicted infarct core (pIC) have poor clinical outcome. However, previous research suggests that this relationship may be relevant for subgroups of patients determined by pretreatment and treatment-related variables while negligible for others. We aimed to identify these variables. METHODS: We included a cohort of 828 patients with acute proximal carotid arterial occlusions imaged with a whole-brain CTP within 8 h from stroke onset. pIC was computed on CTP Maps (cerebral blood flow < 30%), and poor clinical outcome was defined as a 90-day modified Rankin Scale score > 2. Potential mediators of the association between pIC and clinical outcome were evaluated through first-order and advanced interaction analyses in the derivation cohort (n = 654) for obtaining a prediction model. The derived model was further validated in an independent cohort (n = 174). RESULTS: The volume of pIC was significantly associated with poor clinical outcome (OR = 2.19, 95% CI = 1.73 - 2.78, p < 0.001). The strength of this association depended on baseline National Institute of Health Stroke Scale, glucose levels, the use of thrombectomy, and the interaction of age with thrombectomy. The model combining these variables showed good discrimination for predicting clinical outcome in both the derivation cohort and validation cohorts (area under the receiver operating characteristic curve 0.780 (95% CI = 0.746-0.815) and 0.782 (95% CI = 0.715-0.850), respectively). CONCLUSIONS: In patients imaged within 8 h from stroke onset, the association between pIC and clinical outcome is significantly modified by baseline and therapeutic variables. These variables deserve consideration when evaluating the prognostic relevance of pIC. KEY POINTS: •The volume of CT perfusion (CTP) predicted infarct core (pIC) is associated with poor clinical outcome in acute ischemic stroke imaged within 8 h of onset. •The relationship between pIC and clinical outcome may be modified by baseline clinical severity, glucose levels, thrombectomy use, and the interaction of age with thrombectomy. •CTP pIC should be evaluated in an individual basis for predicting clinical outcome in patients imaged within 8 h from stroke onset.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Isquemia Encefálica/complicaciones , Circulación Cerebrovascular , Glucosa , Infarto/complicaciones , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/terapia , Perfusión , Imagen de Perfusión/métodos , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagen , Trombectomía/métodos , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento
10.
J Child Psychol Psychiatry ; 62(6): 780-789, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32951255

RESUMEN

BACKGROUND: The evaluation of child and adolescent offspring of patients with schizophrenia (SzO) or bipolar disorder (BpO) may help understand changes taking place in the brain in individuals at heightened risk for disease during a key developmental period. METHODS: One hundred twenty-eight individuals (33 SzO and 46 BpO, considered jointly as 'Familial High Risk' (FHR), and 49 controls) aged 6-17 years underwent clinical, cognitive and neuroimaging assessment at baseline, 2- and 4-year follow-up. Twenty FHR participants (11 SzO and 9 BpO) developed psychotic spectrum symptoms during follow-up, while 59 FHR participants did not. Magnetic resonance imaging was performed on a 3Tesla scanner; cortical surface reconstruction was applied to measure cortical thickness, surface area and grey matter volume. RESULTS: FHR participants who developed psychotic spectrum symptoms over time showed greater time-related mean cortical thinning than those who did not and than controls. By subgroups, this effect was present in both BpO and SzO in the occipital cortex. At baseline, FHR participants who developed psychotic spectrum symptoms over time had smaller total surface area and grey matter volume than those who did not and than controls. Over time, all FHR participants showed less longitudinal decrease in surface area than controls. In those who developed psychotic spectrum symptoms over time, this effect was driven by BpO, while in those who did not, this was due to SzO, who also showed less grey matter volume reduction. CONCLUSION: The emergence of psychotic spectrum symptoms in FHR was indexed by smaller cross-sectional surface area and progressive cortical thinning. Relative preservation of surface area over time may signal different processes according to familial risk. These findings lay the foundation for future studies aimed at stratification of FHR youth.


Asunto(s)
Trastorno Bipolar , Trastornos Psicóticos , Esquizofrenia , Adolescente , Trastorno Bipolar/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Estudios Transversales , Predisposición Genética a la Enfermedad , Humanos , Imagen por Resonancia Magnética , Trastornos Psicóticos/diagnóstico por imagen , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/genética
11.
Brain ; 143(8): 2454-2473, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32814957

RESUMEN

The epilepsies are commonly accompanied by widespread abnormalities in cerebral white matter. ENIGMA-Epilepsy is a large quantitative brain imaging consortium, aggregating data to investigate patterns of neuroimaging abnormalities in common epilepsy syndromes, including temporal lobe epilepsy, extratemporal epilepsy, and genetic generalized epilepsy. Our goal was to rank the most robust white matter microstructural differences across and within syndromes in a multicentre sample of adult epilepsy patients. Diffusion-weighted MRI data were analysed from 1069 healthy controls and 1249 patients: temporal lobe epilepsy with hippocampal sclerosis (n = 599), temporal lobe epilepsy with normal MRI (n = 275), genetic generalized epilepsy (n = 182) and non-lesional extratemporal epilepsy (n = 193). A harmonized protocol using tract-based spatial statistics was used to derive skeletonized maps of fractional anisotropy and mean diffusivity for each participant, and fibre tracts were segmented using a diffusion MRI atlas. Data were harmonized to correct for scanner-specific variations in diffusion measures using a batch-effect correction tool (ComBat). Analyses of covariance, adjusting for age and sex, examined differences between each epilepsy syndrome and controls for each white matter tract (Bonferroni corrected at P < 0.001). Across 'all epilepsies' lower fractional anisotropy was observed in most fibre tracts with small to medium effect sizes, especially in the corpus callosum, cingulum and external capsule. There were also less robust increases in mean diffusivity. Syndrome-specific fractional anisotropy and mean diffusivity differences were most pronounced in patients with hippocampal sclerosis in the ipsilateral parahippocampal cingulum and external capsule, with smaller effects across most other tracts. Individuals with temporal lobe epilepsy and normal MRI showed a similar pattern of greater ipsilateral than contralateral abnormalities, but less marked than those in patients with hippocampal sclerosis. Patients with generalized and extratemporal epilepsies had pronounced reductions in fractional anisotropy in the corpus callosum, corona radiata and external capsule, and increased mean diffusivity of the anterior corona radiata. Earlier age of seizure onset and longer disease duration were associated with a greater extent of diffusion abnormalities in patients with hippocampal sclerosis. We demonstrate microstructural abnormalities across major association, commissural, and projection fibres in a large multicentre study of epilepsy. Overall, patients with epilepsy showed white matter abnormalities in the corpus callosum, cingulum and external capsule, with differing severity across epilepsy syndromes. These data further define the spectrum of white matter abnormalities in common epilepsy syndromes, yielding more detailed insights into pathological substrates that may explain cognitive and psychiatric co-morbidities and be used to guide biomarker studies of treatment outcomes and/or genetic research.


Asunto(s)
Encéfalo/patología , Síndromes Epilépticos/patología , Sustancia Blanca/patología , Adulto , Imagen de Difusión por Resonancia Magnética/métodos , Femenino , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Masculino , Persona de Mediana Edad
12.
Eur Arch Psychiatry Clin Neurosci ; 271(6): 1133-1139, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30847623

RESUMEN

OBJECTIVE: The objective of the present study is to evaluate cortical thickness (CT) abnormalities using FreeSurfer in adult subjects who had an onset of anorexia nervosa during their adolescence some 20 years previously, and to compare them with control subjects. METHODS: Fifty-four participants, including 26 women who were diagnosed and treated for AN during adolescence some 20 years previously and 28 healthy women of similar age and geographical area were assessed using structured interviews and MRI scans. Prior AN subjects were divided into two groups depending on their current eating disorder status (recovered or not recovered from any eating disorder). In all subjects, CT was measured using FreeSurfer. RESULTS: A significantly lower CT was observed in the eating disorder group than in the control group in the right post-central gyrus and the lateral occipital cortex. The recovered eating disorder group only had lower CT in the post-central gyrus. Within all subjects with prior AN, no correlations were found between lower CT in these areas and clinical variables. DISCUSSION: CT is reduced some 20 years after diagnosis of AN especially in the parietal and precentral areas, even in subjects without any current ED diagnosis.


Asunto(s)
Anorexia Nerviosa , Corteza Cerebral , Adulto , Anorexia Nerviosa/diagnóstico , Anorexia Nerviosa/terapia , Estudios de Casos y Controles , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/patología , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino
13.
Small ; 16(42): e2002735, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32970382

RESUMEN

Complex systems involving networks have attracted strong multidisciplinary attention since they are predicted to sustain fascinating phase transitions in the proximity of the percolation threshold. Developing stable and compact archetypes that allow one to experimentally study physical properties around the percolation threshold remains a major challenge. In nanoscale systems, this achievement is rare since it is tied to the ability to control the intentional disorder and perform a vast statistical analysis of cluster configurations. Here, a self-assembly method to fabricate perfectly ordered structures where random defects can be introduced is presented. Building binary crystals from two types of dielectric nanospheres and selectively removing one of them creates vacancies at random lattice positions that form a complex network of clusters. Vacancy content can be easily controlled and raised even beyond the percolation threshold. In these structures, the distribution of cluster sizes as a function of vacancy density is analyzed. For moderate concentrations, it is found to be homogeneous throughout the structure and in good agreement with the assumption of a random vacancy distribution.

14.
Small ; 15(31): e1902520, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31211494

RESUMEN

Mesoscale self-assembly of particles into supercrystals is important for the design of functional materials such as photonic and plasmonic crystals. However, while much progress has been made in self-assembling supercrystals adopting diverse lattices and using different types of particles, controlling their growth orientation on surfaces has received limited success. Most of the latter orientation control has been achieved via templating methods in which lithographic processes are used to form a patterned surface that acts as a template for particle assembly. Herein, a template-free method to self-assemble (111)-, (100)-, and (110)-oriented face-centered cubic supercrystals of the metal-organic framework ZIF-8 particles by adjusting the amount of surfactant (cetyltrimethylammonium bromide) used is described. It is shown that these supercrystals behave as photonic crystals whose properties depend on their growth orientation. This control on the orientation of the supercrystals dictates the orientation of the composing porous particles that might ultimately facilitate pore orientation on surfaces for designing membranes and sensors.

15.
Small ; 15(52): e1905290, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31650687

RESUMEN

The regulation of temperature is a major energy-consuming process of humankind. Today, around 15% of the global-energy consumption is dedicated to refrigeration and this figure is predicted to triple by 2050, thus linking global warming and cooling needs in a worrying negative feedback-loop. Here, an inexpensive solution is proposed to this challenge based on a single layer of silica microspheres self-assembled on a soda-lime glass. This 2D crystal acts as a visibly translucent thermal-blackbody for above-ambient radiative cooling and can be used to improve the thermal performance of devices that undergo critical heating during operation. The temperature of a silicon wafer is found to be 14 K lower during daytime when covered with the thermal emitter, reaching an average temperature difference of 19 K when the structure is backed with a silver layer. In comparison, the soda-lime glass reference used in the measurements lowers the temperature of the silicon by just 5 K. The cooling power of this simple radiative cooler under direct sunlight is found to be 350 W m-2 when applied to hot surfaces with relative temperatures of 50 K above the ambient. This is crucial to radiatively cool down devices, i.e., solar cells, where an increase in temperature has drastic effects on performance.

16.
Brain ; 141(2): 391-408, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29365066

RESUMEN

Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen's d = -0.24 to -0.73; P < 1.49 × 10-4), and lower thickness in the precentral gyri bilaterally (d = -0.34 to -0.52; P < 4.31 × 10-6). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = -1.73 to -1.91, P < 1.4 × 10-19), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = -0.36 to -0.52; P < 1.49 × 10-4). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = -0.29 to -0.54; P < 1.49 × 10-4). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = -0.27 to -0.51; P < 1.49 × 10-4). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < -0.0018; P < 1.49 × 10-4). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed.


Asunto(s)
Mapeo Encefálico , Encéfalo/diagnóstico por imagen , Epilepsia/patología , Adulto , Encéfalo/patología , Correlación de Datos , Estudios Transversales , Epilepsia/diagnóstico por imagen , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Cooperación Internacional , Imagen por Resonancia Magnética , Masculino , Metaanálisis como Asunto
17.
Mol Cell Biochem ; 440(1-2): 43-51, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28819759

RESUMEN

Melatonin has antitumor activity via several mechanisms including its anti-proliferative and pro-apoptotic effects. Moreover, it has been proven that melatonin in combination with chemotherapeutic agents enhances chemotherapy-triggered apoptosis in several types of cancer. Therefore, this study was intended to evaluate whether melatonin is able to strengthen the anti-cancer potential of different chemotherapeutic drugs in human colorectal adenocarcinoma HT-29 cells. We found that treatment with 20 µM cisplatin (CIS) or 1 mM 5-fluorouracil (5-FU) for 72 h induced a decrease in HT-29 cell viability. Furthermore, 1 mM melatonin significantly (P < 0.05) increased the cytotoxic effects of 5-FU. Likewise, simultaneous stimulation with 1 mM melatonin and 1 mM 5-FU significantly (P < 0.05) enhanced the ratio of cells with an overproduction of intracellular reactive oxygen species and substantially augmented the population of apoptotic cells compared to the treatment with 5-FU alone. Nonetheless, melatonin only displayed moderate chemosensitizing effects in CIS-treated HT-29 cells, as suggested by a slight increment in the fraction of early apoptotic cells that was observed only after 48 h. Consistently, co-stimulation of HT-29 cells with 20 µM CIS or 1 mM 5-FU in the presence of 1 mM melatonin further increased caspase-3 activation. Apart from this, the cytostatic activity displayed by CIS due to S phase arrest was not affected by concomitant stimulation with melatonin. Overall, our results indicate that melatonin increases the sensitivity of HT-29 cells to 5-FU treatment and, consequently, the indolamine could be potentially applied to colorectal adenocarcinoma treatment as a potent chemosensitizing agent.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Neoplasias Colorrectales/tratamiento farmacológico , Fluorouracilo/farmacología , Melatonina/farmacología , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Línea Celular Tumoral , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Humanos
18.
Rev Esp Enferm Dig ; 110(11): 741-742, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30238755

RESUMEN

The rupture of a hepatic hydatid cyst into the intrahepatic bile ducts is one the most common and serious complication of hepatic hydatidosis and occurs in 5-25% of cases. (1, 2, 3). Endoscopic retrograde cholangiopancreatography (ERCP) plays an indisputable role in the diagnosis and treatment of this condition.


Asunto(s)
Equinococosis Hepática/complicaciones , Ictericia Obstructiva/parasitología , Femenino , Humanos , Persona de Mediana Edad , Rotura Espontánea
19.
Mol Cell Biochem ; 412(1-2): 19-26, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26530166

RESUMEN

The cytoprotective role of heat shock proteins (HSPs) has been demonstrated in various cell types however, only few studies have investigated the role of extracellular exposure to HSPs in the survival of human lymphoma cell line U937. In the present study, we investigated the effect of extracellular exposure to four HSPs (HSP90, HSP70, HSP60, and HSP47) on apoptotic cell death induced by either oxidative stress (hydrogen peroxide) or endoplasmic reticulum stress-mediated intracellular calcium overload. It was found that extracellular exposure to HSPs reduced the cytotoxicity induced by hydrogen peroxide, but not that evoked by thapsigargin (a specific inhibitor of cytosolic calcium reuptake which is able to induce endoplasmic reticulum stress with subsequent intracellular calcium overload). Similarly, it was observed that exogenous HSPs were able to suppress the caspase-3 activation induced by hydrogen peroxide. These findings indicate that extracellular HSPs increase the resistance of human lymphoma cell line U937 to apoptotic cell death induced by hydrogen peroxide and diminish oxidative stress-mediated injures.


Asunto(s)
Apoptosis/efectos de los fármacos , Proteínas de Choque Térmico/fisiología , Peróxido de Hidrógeno/toxicidad , Humanos , Tapsigargina/farmacología , Células U937
20.
J Pineal Res ; 60(1): 55-64, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26462739

RESUMEN

Melatonin has antitumor activity via several mechanisms including its antiproliferative and pro-apoptotic effects as well as its potent antioxidant actions, although recent evidence has indicated that melatonin may perform pro-oxidant actions in tumor cells. Therefore, melatonin may be useful in the treatment of tumors in association with chemotherapy drugs. This study was intended to evaluate the in vitro effect of melatonin on the cytotoxic and pro-apoptotic actions of various chemotherapeutic agents in cervical cancer HeLa cells. Herein, we found that both melatonin and three of the chemotherapeutic drugs tested, namely cisplatin (CIS), 5-fluorouracil (5-FU), and doxorubicin, induced a decrease in HeLa cell viability. Furthermore, melatonin significantly increased the cytotoxic effect of such chemotherapeutic agents. Consistently, costimulation of HeLa cells with any chemotherapeutic agent in the presence of melatonin further increased caspase-3 activation, particularly in CIS- and 5-FU-challenged cells. Likewise, concomitant treatments with melatonin and CIS significantly enhanced the ratio of cells entering mitochondrial apoptosis due to reactive oxygen species (ROS) overproduction, substantially augmented the population of apoptotic cells, and markedly enlarged DNA fragmentation compared to the treatments with CIS alone. Nonetheless, melatonin only displayed moderate chemosensitizing effects in 5-FU-stimulated HeLa cells, as suggested by slight increments in the percentage of cells stimulated for ROS production and in the proportion of early apoptotic cells compared to the treatments with 5-FU alone. In summary, our findings provided evidence that in vitro melatonin strongly enhances CIS-induced cytotoxicity and apoptosis in HeLa cells and, hence, the indoleamine could be potentially applied to cervical cancer treatment as a powerful synergistic agent.


Asunto(s)
Apoptosis/efectos de los fármacos , Cisplatino/farmacología , Citotoxinas/farmacología , Fragmentación del ADN/efectos de los fármacos , ADN de Neoplasias/metabolismo , Melatonina/farmacología , Estrés Oxidativo/efectos de los fármacos , Neoplasias del Cuello Uterino/tratamiento farmacológico , Cisplatino/agonistas , Citotoxinas/agonistas , Femenino , Células HeLa , Humanos , Melatonina/agonistas , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/patología
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