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During the course of exploring crystallization conditions in generating metal-organic frameworks (MOFs) for use in the crystalline sponge method, two discrete metal-organic complexes, namely, aqua[2,4,6-tris(pyridin-4-yl)-1,3,5-triazine]zinc(II) bromide, [Zn(C18H12N6)(H2O)]Br2, and aqua[2,4,6-tris(pyridin-4-yl)-1,3,5-triazine]zinc(II) chloride, [Zn(C18H12N6)(H2O)]Cl2, were encountered. Structures in the orthorhombic space group Pnma (No. 62) for the bromide congener at 299â K and the chloride congener at 100â K were obtained. A phase transition for the bromide congener occurred upon cooling from 299 to 100â K, yielding a crystal polymorph with four domains that exhibits monoclinic P21/m space-group symmetry (No. 11), which arises from conformational changes. The main intramolecular contacts that contribute to the crystal packing in all observed structures are H...H, Halide...H/H...Halide, C...H/H...C, and N...H/H...N. Intramolecular hydrogen bonding between the Zn-bound water and non-Zn-bound pyridyl N atoms is a prominent feature within the three-dimensional networks. Aromatic π-stacking between the non-Zn-bound pyridine rings and contacts involving the halide ligands further stabilize the crystal packing.
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Developmental stuttering (DS) is a neurodevelopmental speech-motor disorder characterized by symptoms such as blocks, repetitions, and prolongations. Persistent DS often has a significant negative impact on quality of life, and interventions for it have limited efficacy. Herein, we briefly review existing research on the neurophysiological underpinnings of DS -specifically, brain metabolic and default mode/social-cognitive networks (DMN/SCN) anomalies- arguing that psychedelic compounds might be considered and investigated (e.g., in randomized clinical trials) for treatment of DS. The neural background of DS is likely to be heterogeneous, and some contribution from genetically determinants of metabolic deficiencies in the basal ganglia and speech-motor cortical regions are thought to play a role in appearance of DS symptoms, which possibly results in a cascade of events contributing to impairments in speech-motor execution. In persistent DS, the difficulties of speech are often linked to a series of associated aspects such as social anxiety and social avoidance. In this context, the SCN and DMN (also influencing a series of fronto-parietal, somato-motor, and attentional networks) may have a role in worsening dysfluencies. Interestingly, brain metabolism and SCN/DMN connectivity can be modified by psychedelics, which have been shown to improve clinical evidence of some psychiatric conditions (e.g., depression, post-traumatic stress disorder, etc.) associated with psychological constructs such as rumination and social anxiety, which also tend to be present in persistent DS. To date, while there have been no controlled trials on the effects of psychedelics in DS, anecdotal evidence suggests that these agents may have beneficial effects on stuttering and its associated characteristics. We suggest that psychedelics warrant investigation in DS.
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OBJECTIVE: When the peritoneal cavity cannot serve as the distal shunt terminus, nonperitoneal shunts, typically terminating in the atrium or pleural space, are used. The comparative effectiveness of these two terminus options has not been evaluated. The authors directly compared shunt survival and complication rates for ventriculoatrial (VA) and ventriculopleural (VPl) shunts in a pediatric cohort. METHODS: The Hydrocephalus Clinical Research Network Core Data Project was used to identify children ≤ 18 years of age who underwent either VA or VPl shunt insertion. The primary outcome was time to shunt failure. Secondary outcomes included distal site complications and frequency of shunt failure at 6, 12, and 24 months. RESULTS: The search criteria yielded 416 children from 14 centers with either a VA (n = 318) or VPl (n = 98) shunt, including those converted from ventriculoperitoneal shunts. Children with VA shunts had a lower median age at insertion (6.1 years vs 12.4 years, p < 0.001). Among those children with VA shunts, a hydrocephalus etiology of intraventricular hemorrhage (IVH) secondary to prematurity comprised a higher proportion (47.0% vs 31.2%) and myelomeningocele comprised a lower proportion (17.8% vs 27.3%) (p = 0.024) compared with those with VPl shunts. At 24 months, there was a higher cumulative number of revisions for VA shunts (48.6% vs 38.9%, p = 0.038). When stratified by patient age at shunt insertion, VA shunts in children < 6 years had the lowest shunt survival rate (p < 0.001, log-rank test). After controlling for age and etiology, multivariable analysis did not find that shunt type (VA vs VPl) was predictive of time to shunt failure. No differences were found in the cumulative frequency of complications (VA 6.0% vs VPl 9.2%, p = 0.257), but there was a higher rate of pneumothorax in the VPl cohort (3.1% vs 0%, p = 0.013). CONCLUSIONS: Shunt survival was similar between VA and VPl shunts, although VA shunts are used more often, particularly in younger patients. Children < 6 years with VA shunts appeared to have the shortest shunt survival, which may be a result of the VA group having more cases of IVH secondary to prematurity; however, when age and etiology were included in a multivariable model, shunt location (atrium vs pleural space) was not associated with time to failure. The baseline differences between children treated with a VA versus a VPl shunt likely explain current practice patterns.
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Research points to neurofunctional differences underlying fluent speech between stutterers and non-stutterers. Considerably less work has focused on processes that underlie stuttered vs. fluent speech. Additionally, most of this research has focused on speech motor processes despite contributions from cognitive processes prior to the onset of stuttered speech. We used MEG to test the hypothesis that reactive inhibitory control is triggered prior to stuttered speech. Twenty-nine stutterers completed a delayed-response task that featured a cue (prior to a go cue) signaling the imminent requirement to produce a word that was either stuttered or fluent. Consistent with our hypothesis, we observed increased beta power likely emanating from the right pre-supplementary motor area (R-preSMA)-an area implicated in reactive inhibitory control-in response to the cue preceding stuttered vs. fluent productions. Beta power differences between stuttered and fluent trials correlated with stuttering severity and participants' percentage of trials stuttered increased exponentially with beta power in the R-preSMA. Trial-by-trial beta power modulations in the R-preSMA following the cue predicted whether a trial would be stuttered or fluent. Stuttered trials were also associated with delayed speech onset suggesting an overall slowing or freezing of the speech motor system that may be a consequence of inhibitory control. Post-hoc analyses revealed that independently generated anticipated words were associated with greater beta power and more stuttering than researcher-assisted anticipated words, pointing to a relationship between self-perceived likelihood of stuttering (i.e., anticipation) and inhibitory control. This work offers a neurocognitive account of stuttering by characterizing cognitive processes that precede overt stuttering events.
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Stuttering poses challenges to social, occupational, and educational aspects of life. Traditional behavioral therapies can be helpful but effects are often limited. Pharmaceutical treatments have been explored but there are no FDA-approved treatments for stuttering. Interest has grown in the potential use of classic psychedelics, including psilocybin and LSD, which have shown effectiveness in treating disorders with similar symptoms (e.g., anxiety, depression, PTSD). The potential effects of psychedelics on stuttering have not been explored. We conducted a preliminary investigation of self-identified stutterers who report their experiences taking classic psychedelics on the online messaging forum, Reddit. We qualitatively analyzed 114 publicly available posts, extracting meaningful units and assigning descriptor codes inductively. We then deductively organized responses into an established framework of psychedelics which includes behavioral, emotional, cognitive, belief-based, and social effects. These effects were subsequently grouped under organizing themes (positive, negative, neutral). Descriptive statistics revealed that the majority of users (74.0%) reported positive overall short-term effects particularly related to behavioral and emotional change (e.g., reduced stuttering and anxiety), but negative (9.6%), mixed (positive and negative; 4.8%), and neutral overall experiences (11.6%) were also reported. The results support the possibility that psychedelics may impact stuttering, but caution must be applied in their interpretation given the entirely uncontrolled research setting and potential adverse health effects of psychedelics as reported elsewhere. While these results do not encourage the use of psychedelics by stutterers, they suggest that future work could examine the impact of psychedelics on stuttering under supervised and in clinically controlled settings.
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Objective: The objective of this study was to examine the impact of the introduction of the Universal Anaesthesia Machine (UAM), a device designed for use in clinical environments with limited clinical perioperative resources, on the choice of general anesthesia technique and safe anesthesia practice in a tertiary-care hospital in Sierra Leone. Methods: We introduced an anesthesia machine (UAM) into Connaught Hospital, Freetown, Sierra Leone. We conducted a prospective observational study of anesthesia practice and an examination of perioperative clinical parameters among surgical patients at the hospital to determine the usability of the device, its impact on anesthesia capacity, and changes in general anesthesia technique. Findings: We observed a shift from the use of ketamine total intravenous anesthesia to inhalational anesthesia. This shift was most demonstrable in anesthesia care for appendectomies and surgical wound management. In 10 of 17 power outages that occurred during inhalational general anesthesia, anesthesia delivery was uninterrupted because inhalational anesthesia was being delivered with the UAM. Conclusion: Anesthesia technologies tailored to overcome austere environmental conditions can support the delivery of safe anesthesia care while maintaining fidelity to recommended international anesthesia practice standards.
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OBJECTIVE: The PEDSPINE I and PEDSPINE II scores were developed to determine when patients require advanced imaging to rule out cervical spine injury (CSI) in children younger than 3 years of age with blunt trauma. This study aimed to evaluate these scores in an institutional cohort. METHODS: The authors identified patients younger than 3 years with blunt trauma who received cervical spine MRI from their institution's prospective database from 2012 to 2015. Patient demographics, injury characteristics, and imaging were compared between patients with and without CSI using chi-square and Wilcoxon rank-sum tests. RESULTS: Eighty-eight patients were identified, 8 (9%) of whom had CSI on MRI. The PEDSPINE I system had a higher sensitivity (50% vs 25%) and negative predictive value (93% vs 92%), whereas PEDSPINE II had a higher specificity (91% vs 65%) and positive predictive value (22% vs 13%). Patients with CSI missed by the scores had mild, radiologically significant ligamentous injuries detected on MRI. Both models would have recommended advanced imaging for the patient who required halo-vest fixation (risk profile: no CSI, 81.9%; ligamentous, 10.1%; osseous, 8.0%). PEDSPINE I would have prevented 52 (65%) of 80 uninjured patients from receiving advanced imaging, whereas PEDSPINE II would have prevented 73 (91%). Using PEDSPINE I, 10 uninjured patients (13%) could have avoided intubation for imaging. PEDSPINE II would not have spared any patients intubation. CONCLUSIONS: Current cervical spine clearance algorithms are not sensitive or specific enough to determine the need for advanced imaging in children. However, these scores can be used as a reference in conjunction with physicians' clinical impressions to reduce unnecessary imaging.
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Vértebras Cervicales , Imagen por Resonancia Magnética , Traumatismos Vertebrales , Heridas no Penetrantes , Humanos , Heridas no Penetrantes/diagnóstico por imagen , Masculino , Femenino , Vértebras Cervicales/lesiones , Vértebras Cervicales/diagnóstico por imagen , Lactante , Preescolar , Traumatismos Vertebrales/diagnóstico por imagen , Sensibilidad y Especificidad , Estudios Retrospectivos , Estudios Prospectivos , Valor Predictivo de las PruebasRESUMEN
OBJECTIVE: Congenital anomalies of the atlanto-occipital articulation may be present in patients with Chiari malformation type I (CM-I). However, it is unclear how these anomalies affect the biomechanical stability of the craniovertebral junction (CVJ) and whether they are associated with an increased incidence of occipitocervical fusion (OCF) following posterior fossa decompression (PFD). The objective of this study was to determine the prevalence of condylar hypoplasia and atlas anomalies in children with CM-I and syringomyelia. The authors also investigated the predictive contribution of these anomalies to the occurrence of OCF following PFD (PFD+OCF). METHODS: The authors analyzed the prevalence of condylar hypoplasia and atlas arch anomalies for patients in the Park-Reeves Syringomyelia Research Consortium database who underwent PFD+OCF. Condylar hypoplasia was defined by an atlanto-occipital joint axis angle (AOJAA) ≥ 130°. Atlas assimilation and arch anomalies were identified on presurgical radiographic imaging. This PFD+OCF cohort was compared with a control cohort of patients who underwent PFD alone. The control group was matched to the PFD+OCF cohort according to age, sex, and duration of symptoms at a 2:1 ratio. RESULTS: Clinical features and radiographic atlanto-occipital joint parameters were compared between 19 patients in the PFD+OCF cohort and 38 patients in the PFD-only cohort. Demographic data were not significantly different between cohorts (p > 0.05). The mean AOJAA was significantly higher in the PFD+OCF group than in the PFD group (144° ± 12° vs 127° ± 6°, p < 0.0001). In the PFD+OCF group, atlas assimilation and atlas arch anomalies were identified in 10 (53%) and 5 (26%) patients, respectively. These anomalies were absent (n = 0) in the PFD group (p < 0.001). Multivariate regression analysis identified the following 3 CVJ radiographic variables that were predictive of OCF occurrence after PFD: AOJAA ≥ 130° (p = 0.01), clivoaxial angle < 125° (p = 0.02), and occipital condyle-C2 sagittal vertical alignment (C-C2SVA) ≥ 5 mm (p = 0.01). A predictive model based on these 3 factors accurately predicted OCF following PFD (C-statistic 0.95). CONCLUSIONS: The authors' results indicate that the occipital condyle-atlas joint complex might affect the biomechanical integrity of the CVJ in children with CM-I and syringomyelia. They describe the role of the AOJAA metric as an independent predictive factor for occurrence of OCF following PFD. Preoperative identification of these skeletal abnormalities may be used to guide surgical planning and treatment of patients with complex CM-I and coexistent osseous pathology.
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Malformación de Arnold-Chiari , Articulación Atlantooccipital , Atlas Cervical , Hueso Occipital , Fusión Vertebral , Siringomielia , Humanos , Malformación de Arnold-Chiari/cirugía , Malformación de Arnold-Chiari/diagnóstico por imagen , Siringomielia/cirugía , Siringomielia/diagnóstico por imagen , Femenino , Masculino , Atlas Cervical/anomalías , Atlas Cervical/cirugía , Atlas Cervical/diagnóstico por imagen , Niño , Hueso Occipital/cirugía , Hueso Occipital/diagnóstico por imagen , Hueso Occipital/anomalías , Fusión Vertebral/métodos , Adolescente , Articulación Atlantooccipital/diagnóstico por imagen , Articulación Atlantooccipital/cirugía , Articulación Atlantooccipital/anomalías , Resultado del Tratamiento , Preescolar , Descompresión Quirúrgica/métodos , Estudios Retrospectivos , Vértebras Cervicales/cirugía , Vértebras Cervicales/anomalías , Vértebras Cervicales/diagnóstico por imagenRESUMEN
OBJECTIVE: The aim of this study was to delineate the clinical and socioeconomic variables associated with shunt revision in pediatric patients presenting to the emergency department (ED) with concerns of ventricular shunt malfunction. METHODS: A retrospective analysis of pediatric ED consultations for shunt malfunction over a 1-year period was conducted, examining clinical symptoms, radiographic findings, and socioeconomic variables. Sensitivities, specificities, and positive and negative predictive values were calculated for each presenting symptom collected. Logistic regression models were used to estimate the odds ratios for shunt revision based on these variables, and multivariate analyses were used to adjust for potential confounders. RESULTS: Of the 271 ED visits from 137 patients, 19.2% resulted in shunt revision. Increased ventricle size on imaging (OR 11.38, p < 0.001), shunt site swelling (OR 9.04, p = 0.01), bradycardia (OR 7.08, p < 0.001), and lethargy (OR 5.77, p < 0.001) were significantly associated with shunt revision. Seizure-like activity was inversely related to revision needs (OR 0.24, p < 0.001). Patients with private or self-pay insurance were more likely to undergo revision compared with those with public insurance (p = 0.028). Multivariate analysis further confirmed the significant associations of increased ventricle size, lethargy, and bradycardia with shunt revision, while also revealing that seizure-like activity inversely affected the likelihood of revision. Patients with severe cognitive and language disabilities were more likely to be admitted to the hospital from the ED but were not more likely to undergo revision. CONCLUSIONS: Clinical signs such as increased ventricle size, shunt site swelling, bradycardia, and lethargy may be strong predictors of the need for shunt revision in pediatric patients presenting to the ED with concerns of shunt malfunction. Socioeconomic factors play a less clear role in predicting shunt revision and admission from the ED; however, the nature of their influence is unclear. These findings can help inform clinical decision-making and optimize resource utilization in the ED.
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Servicio de Urgencia en Hospital , Humanos , Masculino , Femenino , Estudios Retrospectivos , Niño , Preescolar , Lactante , Adolescente , Reoperación/estadística & datos numéricos , Hidrocefalia/cirugía , Factores Socioeconómicos , Derivaciones del Líquido Cefalorraquídeo , Falla de EquipoRESUMEN
PURPOSE: To discuss among neuroscientists and community speech-language pathologists what brain imaging research means to clinicians. METHOD: Two university neuroscientists and two speech-language pathologists in private practice discussed the matter. Written conversational turns in an exchange were limited to 100 words each. When that written dialogue was concluded, each participant provided 200 words of final reflection about the matter. RESULT: For now, neuroscience treatments are not available for clinicians to use. But sometime in the future, a critical mass of neuroscientists will likely produce such treatments. The neuroscientists expressed diverse views about the methods that might be used for that to occur. CONCLUSION: Neuroscience does have practical clinical application at present and, in a way, that does not exclude a concurrent influence of the social model of disability. As such, the current practices of clinicians are supported by basic neuroscience research.
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OBJECTIVE: The Hydrocephalus Clinical Research Network (HCRN) conducted a prospective study 1) to determine if a new, better-performing version of the Endoscopic Third Ventriculostomy Success Score (ETVSS) could be developed, 2) to explore the performance characteristics of the original ETVSS in a modern endoscopic third ventriculostomy (ETV) cohort, and 3) to determine if the addition of radiological variables to the ETVSS improved its predictive abilities. METHODS: From April 2008 to August 2019, children (corrected age ≤ 17.5 years) who underwent a first-time ETV for hydrocephalus were included in a prospective multicenter HCRN study. All children had at least 6 months of clinical follow-up and were followed since the index ETV in the HCRN Core Data Registry. Children who underwent choroid plexus cauterization were excluded. Outcome (ETV success) was defined as the lack of ETV failure within 6 months of the index procedure. Kaplan-Meier curves were constructed to evaluate time-dependent variables. Multivariable binary logistic models were built to evaluate predictors of ETV success. Model performance was evaluated with Hosmer-Lemeshow and Harrell's C statistics. RESULTS: Seven hundred sixty-one children underwent a first-time ETV. The rate of 6-month ETV success was 76%. The Hosmer-Lemeshow and Harrell's C statistics of the logistic model containing more granular age and etiology categorizations did not differ significantly from a model containing the ETVSS categories. In children ≥ 12 months of age with ETVSSs of 50 or 60, the original ETVSS underestimated success, but this analysis was limited by a small sample size. Fronto-occipital horn ratio (p = 0.37), maximum width of the third ventricle (p = 0.39), and downward concavity of the floor of the third ventricle (p = 0.63) did not predict ETV success. A possible association between the degree of prepontine adhesions on preoperative MRI and ETV success was detected, but this did not reach statistical significance. CONCLUSIONS: This modern, multicenter study of ETV success shows that the original ETVSS continues to demonstrate good predictive ability, which was not substantially improved with a new success score. There might be an association between preoperative prepontine adhesions and ETV success, and this needs to be evaluated in a future large prospective study.
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Hidrocefalia , Tercer Ventrículo , Ventriculostomía , Humanos , Ventriculostomía/métodos , Hidrocefalia/cirugía , Hidrocefalia/diagnóstico por imagen , Femenino , Masculino , Tercer Ventrículo/cirugía , Tercer Ventrículo/diagnóstico por imagen , Niño , Preescolar , Estudios Prospectivos , Lactante , Resultado del Tratamiento , Adolescente , Neuroendoscopía/métodos , Estudios de SeguimientoRESUMEN
BACKGROUND: Cellular senescence can have positive and negative effects on the body, including aiding in damage repair and facilitating tumor growth. Adamantinomatous craniopharyngioma (ACP), the most common pediatric sellar/suprasellar brain tumor, poses significant treatment challenges. Recent studies suggest that senescent cells in ACP tumors may contribute to tumor growth and invasion by releasing a senesecence-associated secretory phenotype. However, a detailed analysis of these characteristics has yet to be completed. METHODS: We analyzed primary tissue samples from ACP patients using single-cell, single-nuclei, and spatial RNA sequencing. We performed various analyses, including gene expression clustering, inferred senescence cells from gene expression, and conducted cytokine signaling inference. We utilized LASSO to select essential gene expression pathways associated with senescence. Finally, we validated our findings through immunostaining. RESULTS: We observed significant diversity in gene expression and tissue structure. Key factors such as NFKB, RELA, and SP1 are essential in regulating gene expression, while senescence markers are present throughout the tissue. SPP1 is the most significant cytokine signaling network among ACP cells, while the Wnt signaling pathway predominantly occurs between epithelial and glial cells. Our research has identified links between senescence-associated features and pathways, such as PI3K/Akt/mTOR, MYC, FZD, and Hedgehog, with increased P53 expression associated with senescence in these cells. CONCLUSIONS: A complex interplay between cellular senescence, cytokine signaling, and gene expression pathways underlies ACP development. Further research is crucial to understand how these elements interact to create novel therapeutic approaches for patients with ACP.
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Senescencia Celular , Craneofaringioma , Aprendizaje Automático , Neoplasias Hipofisarias , Humanos , Craneofaringioma/metabolismo , Craneofaringioma/patología , Craneofaringioma/genética , Neoplasias Hipofisarias/patología , Neoplasias Hipofisarias/metabolismo , Neoplasias Hipofisarias/genética , Biomarcadores de Tumor/metabolismo , Biomarcadores de Tumor/genética , Fenotipo , Regulación Neoplásica de la Expresión Génica , Niño , Masculino , FemeninoRESUMEN
The popularity of oats (Avena sativa) continues to increase in the cereal market due to their health benefits. The recent domestication of Avena magna, a Moroccan oat, presents an opportunity to enhance these benefits due to their higher nutritional composition. As the impact of microclimates on A. magna grain composition has not been explored, this study evaluates twelve A. magna ssp. domestica lines across three Moroccan locations, providing new data into microclimate effects on key grain characteristics. Significant variability is observed among lines and sites for nutrients, with mean protein, fat, and dietary fiber contents at 23.1%, 8.38%, and 7.23%, respectively. High protein levels, reaching 27.1% in Alnif and 26.5% in El Kbab, surpass the 'Avery' control (21.7% and 24.2%) in these environments. Groats from Bouchane exhibited elevated fat and fiber contents (10.2% and 9.94%) compared to the control (8.83% and 7.36%). While ß-glucan levels remain consistent at 2.53%, a negative correlation between protein content, fat, and starch was observed. A. magna lines exhibited higher levels of iron (7.50 × 10-3 g/100 g DM) and zinc (3.40 × 10-3 g/100 g DM) compared to other cereals. Environmental conditions significantly influence grain quality, with El Kbab yielding higher protein and ash contents, as well as Bouchane having increased fat, fiber, and starch. Stability analysis indicates that fat content was more influenced by the environment, while 25% of protein variability is influenced by genetics. Lines AT3, AT5, AT6, AT13, and AT15 consistently exceeds both the mean for protein and fiber across all sites, emphasizing their potential nutritional value. This study highlights the potential of A. magna ssp. domestica to address nutritional insecurity, particularly for protein, iron, and zinc in domestic settings.
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To elucidate the pathogenesis of vein of Galen malformations (VOGMs), the most common and most severe of congenital brain arteriovenous malformations, we performed an integrated analysis of 310 VOGM proband-family exomes and 336,326 human cerebrovasculature single-cell transcriptomes. We found the Ras suppressor p120 RasGAP (RASA1) harbored a genome-wide significant burden of loss-of-function de novo variants (2042.5-fold, p = 4.79 x 10-7). Rare, damaging transmitted variants were enriched in Ephrin receptor-B4 (EPHB4) (17.5-fold, p = 1.22 x 10-5), which cooperates with p120 RasGAP to regulate vascular development. Additional probands had damaging variants in ACVRL1, NOTCH1, ITGB1, and PTPN11. ACVRL1 variants were also identified in a multi-generational VOGM pedigree. Integrative genomic analysis defined developing endothelial cells as a likely spatio-temporal locus of VOGM pathophysiology. Mice expressing a VOGM-specific EPHB4 kinase-domain missense variant (Phe867Leu) exhibited disrupted developmental angiogenesis and impaired hierarchical development of arterial-capillary-venous networks, but only in the presence of a "second-hit" allele. These results illuminate human arterio-venous development and VOGM pathobiology and have implications for patients and their families.
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Enfermedades Vasculares , Malformaciones de la Vena de Galeno , Humanos , Animales , Ratones , Malformaciones de la Vena de Galeno/genética , Malformaciones de la Vena de Galeno/patología , Células Endoteliales/patología , Mutación , Transducción de Señal/genética , Mutación Missense , Proteínas Activadoras de GTPasa/genética , Receptores de Activinas Tipo II/genética , Proteína Activadora de GTPasa p120/genéticaRESUMEN
We report a resonant cavity infrared detector (RCID) with an InAsSb/InAs superlattice absorber with a thickness of only ≈ 100â nm, a 33-period GaAs/Al0.92Ga0.08As distributed Bragg reflector bottom mirror, and a Ge/SiO2/Ge top mirror. At a low bias voltage of 150â mV, the external quantum efficiency (EQE) reaches 58% at the resonance wavelength λres ≈ 4.6â µm, with linewidth δλ = 19-27â nm. The thermal background current for a realistic system scenario with f/4 optic that views a 300â K scene is estimated by integrating the photocurrent generated by background spanning the entire mid-IR spectral band (3-5â µm). The resulting specific detectivity is a factor of 3 lower than for a state-of-the-art broadband HgCdTe device at 300â K, where dark current dominates the noise. However, at 125â K where the suppression of background noise becomes critical, the estimated specific detectivity D* of 5.5 × 1012â cm Hz½/W is more than 3× higher. This occurs despite a non-optimal absorber cut-off that causes the EQE to decrease rapidly with decreasing temperature, e.g., to 33% at 125â K. The present RCID's advantage over the broadband device depends critically on its low EQE at non-resonance wavelengths: ≤ 1% in the range 3.9-5.5â µm. Simulations using NRL MULTIBANDS indicate that impact ionization in the bottom contact and absorber layers dominates the dark current at near ambient temperatures. We expect future design modifications to substantially enhance D* throughout the investigated temperature range of 100-300â K.
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PURPOSE: Previous work shows that linguistic features (e.g., word length, word frequency) impact the predictability of stuttering events. Most of this work has been conducted using reading tasks. Our study examined how linguistic features impact the predictability of stuttering events during spontaneous speech. METHODS: The data were sourced from the FluencyBank database and consisted of interviews with 35 adult stutterers (27,009 words). Three logistic regression mixed models were fit as the primary analyses: one model with four features (i.e., initial phoneme, grammatical function, word length, and word position within a sentence), a second model with six features (i.e., the features from the previous model plus word frequency and neighborhood density), and a third model with nine features (i.e., the features from the previous model plus bigram frequency, word concreteness, and typical age of word acquisition). We compared our models using the Area Under the Curve statistic. RESULTS: The four-feature model revealed that initial phoneme, grammatical function, and word length were predictive of stuttering events. The six-feature model revealed that initial phoneme, word length, word frequency, and neighborhood density were predictive of stuttering events. The nine-feature model was not more predictive than the six-feature model. CONCLUSION: Linguistic features that were previously found to be predictive of stuttering during reading were predictive of stuttering during spontaneous speech. The results indicate the influence of linguistic processes on the predictability of stuttering events such that words associated with increased planning demands (e.g., longer words, low frequency words) were more likely to be stuttered.
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Habla , Tartamudeo , Adulto , Humanos , Tartamudeo/diagnóstico , Medición de la Producción del Habla/métodos , Lingüística/métodos , LenguajeRESUMEN
Pediatric patients with moyamoya arteriopathy are at high risk for developing new onset transient or permanent neurologic deficits secondary to cerebral hypoperfusion, particularly in the perioperative period. It is therefore essential to carefully manage these patients in a multidisciplinary, coordinated effort to reduce the risk of new permanent neurologic deficits. However, little has been published on perioperative management of pediatric patients with moyamoya, particularly in the early postoperative period during intensive care unit admission. Our pediatric neurocritical care team sought to create a multidisciplinary periprocedural evidence- and consensus-based care pathway for high-risk pediatric patients with moyamoya arteriopathy undergoing anesthesia for any reason to decrease the incidence of periprocedural stroke or transient ischemic attack (TIA). We reviewed the literature to identify risk factors associated with perioperative stroke or TIA among patients with moyamoya and to gather data supporting specific perioperative management strategies. A multidisciplinary team from pediatric anesthesia, neurocritical care, nursing, child life, neurosurgery, interventional neuroradiology, neurology, and hematology created a care pathway for children with moyamoya undergoing anesthesia, classifying them as either high or standard risk, and applying an individualized perioperative management plan to high-risk patients. The incidence of neurologic sequelae before and after pathway implementation will be compared in future studies.
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Medulloblastoma is the most common malignant pediatric brain tumor and is associated with significant morbidity and mortality in the pediatric population. Despite the use of multiple therapeutic approaches consisting of surgical resection, craniospinal irradiation, and multiagent chemotherapy, the prognosis of many patients with medulloblastoma remains dismal. Additionally, the high doses of radiation and the chemotherapeutic agents used are associated with significant short- and long-term complications and adverse effects, most notably neurocognitive delay. Hence, there is an urgent need for the development and clinical integration of targeted treatment regimens with greater efficacy and superior safety profiles. Since the adoption of the molecular-based classification of medulloblastoma into wingless (WNT) activated, sonic hedgehog (SHH) activated, group 3, and group 4, research efforts have been directed towards unraveling the genetic, epigenetic, transcriptomic, and proteomic profiles of each subtype. This review aims to delineate the progress that has been made in characterizing the neurodevelopmental and molecular features of each medulloblastoma subtype. It further delves into the implications that these characteristics have on the development of subgroup-specific targeted therapeutic agents. Furthermore, it highlights potential future avenues for combining multiple agents or strategies in order to obtain augmented effects and evade the development of treatment resistance in tumors.
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PURPOSE OF REVIEW: Regardless of the etiology, if pain persists chronically, it can detrimentally impact multiple aspects of a patient's well-being. Both physical and psychological effects are significant in many chronic pain patients. In this regard, psychological consequences can alter a patient's quality of life, functionality, and social functioning. Opioids have been the long-established gold standard for acute pain treatment in settings such as the postoperative period. An alternative to opioids in pain management has been highly sought after. Through a non-selective mechanism, cebranopadol is a first-in-class oral drug which combines agonism of the mu and nociceptin opioid peptide (NOP) receptors to provide improved analgesia, while reducing the occurrence of many typically opioid side effects. This manuscript is a narrative review of the possible use of cebranopadol in pain management. RECENT FINDINGS: In pre-clinical studies, cebranopadol was similar to morphine in its pain control efficacy. In a phase IIa trial, cebranopadol was superior to placebo in reducing pain. In a randomized clinical trial, cebranopadol was superior to morphine. Another study concluded that cebranopadol had a lower misuse potential when compared to hydromorphone. In summary, cebranopadol offers new opportunities in treating chronic moderate to severe pain, while also countering risks of addiction. Additional studies are warranted to further evaluate the safety and efficacy of cebranopadol. In this regard, cebranopadol could prove to be a promising alternative to current pain treatment options.