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1.
Nature ; 567(7748): E12, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30837739

RESUMEN

We would like to correct the sentence in our Letter "However, both our detailed computational analysis (see Supplementary Fig. 2) and past computations13-15 suggest that such enhancements are not anticipated for metallic spheres, and very small increases (by a factor of a few) may be expected for dielectric spheres or metallic cylinders." The work of ref. 13 is not limited to the structures described in this statement but also presents a computational study of radiative heat transfer between rectangular dielectric membranes that is consistent with our experimental and computational analysis, and supports our findings that the blackbody limit can be overcome in the far-field. See accompanying Amendment. The original Letter has not been corrected online.

2.
Chemistry ; 30(36): e202400672, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38623589

RESUMEN

The solvent-free elimination of sulfinic acid and aromatization of 1,6-trans-substituted bis(arylsulfone) trienes is reported. It is shown that sublimation can be used as a 'green' method to combine the thermal transformation of six trienes and the crystal growth of the resulting 4-(phenylsulfonyl)biphenyls. When the sublimation conditions are carefully controlled, high quality single crystals of the 4-(phenylsulfonyl)biphenyls are obtained. Theoretical modelling of the reaction using the simplified triene Ph-(CH)6-SO2H showed that the cyclization is energetically feasible and that the complete conversion is possible during the timescale of the sublimation. At temperatures slightly higher than the optimum sublimation temperature two of the trienes transformed into 1,4-cyclohexadienes that did not eliminate phenylsulfinic acid. A reaction mechanism involving a 1,3-hydrogen shift induced by free PhS• radicals is proposed for the formation of the 1,4-cyclohexadienes.

3.
J Surg Oncol ; 129(4): 691-699, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38037311

RESUMEN

BACKGROUND: Over recent years, there has been increasing adoption of minimally invasive surgery (MIS) in the treatment of adrenocortical carcinoma (ACC). However, MIS has been associated with noncurative resection and locoregional recurrence. We aimed to identify risk factors for margin-positivity among patients who undergo MIS resection for ACC. We hypothesized that a simple nomogram can accurately identify patients most suitable for curative MIS resection. METHODS: Curative-intent resections for ACC were identified through the National Cancer Database spanning 2010-2018. Trends in MIS utilization were reported using Pearson correlation coefficients. Factors associated with margin-positive resection were identified among preoperatively available variables using multivariable logistic regression, then incorporated into a predictive model. Model quality was cross validated using an 80% training data set and 20% test data set. RESULTS: Among 1260 ACC cases, 38.6% (486) underwent MIS resection. MIS utilization increased over time at nonacademic centers (R = 0.818, p = 0.007), but not at academic centers (R = 0.009, p = 0.982). Factors associated with margin-positive MIS resection were increasing age, nonacademic center (odds ratio [OR]: 1.8, p = 0.006), cT3 (OR: 4.7, p < 0.001) or cT4 tumors (OR: 14.6, p < 0.001), and right-sided tumors (OR: 2.0, p = 0.006). A predictive model incorporating these four factors produced favorable c-statistics of 0.75 in the training data set and 0.72 in the test data set. A pragmatic nomogram was created to enable bedside risk stratification. CONCLUSIONS: An increasing proportion of ACC are resected via minimally invasive operations, particularly at nonacademic centers. Patient selection based on a few key factors can minimize the risk of noncurative surgery.


Asunto(s)
Neoplasias de la Corteza Suprarrenal , Carcinoma Corticosuprarrenal , Laparoscopía , Humanos , Carcinoma Corticosuprarrenal/cirugía , Carcinoma Corticosuprarrenal/patología , Nomogramas , Procedimientos Quirúrgicos Mínimamente Invasivos/efectos adversos , Neoplasias de la Corteza Suprarrenal/cirugía , Neoplasias de la Corteza Suprarrenal/patología , Estudios Retrospectivos
4.
Nature ; 561(7722): 216-221, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30177825

RESUMEN

Radiative heat transfer (RHT) has a central role in entropy generation and energy transfer at length scales ranging from nanometres to light years1. The blackbody limit2, as established in Max Planck's theory of RHT, provides a convenient metric for quantifying rates of RHT because it represents the maximum possible rate of RHT between macroscopic objects in the far field-that is, at separations greater than Wien's wavelength3. Recent experimental work has verified the feasibility of overcoming the blackbody limit in the near field4-7, but heat-transfer rates exceeding the blackbody limit have not previously been demonstrated in the far field. Here we use custom-fabricated calorimetric nanostructures with embedded thermometers to show that RHT between planar membranes with sub-wavelength dimensions can exceed the blackbody limit in the far field by more than two orders of magnitude. The heat-transfer rates that we observe are in good agreement with calculations based on fluctuational electrodynamics. These findings may be directly relevant to various fields, such as energy conversion, atmospheric sciences and astrophysics, in which RHT is important.

5.
Clin Gerontol ; : 1-11, 2024 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-38762776

RESUMEN

OBJECTIVES: To describe nursing home (NH) characteristics associated with antipsychotic use and test whether associations changed after implementation of the National Partnership to Improve Dementia Care's antipsychotic reduction initiative (ARI). METHODS: Longitudinal quasi-experimental design using data from multiple sources and piecewise linear mixed models were used for statistical analyses. RESULTS: There was a significant decrease in monthly antipsychotic use across the study period (pre-ARI b = -0.0003, p <.001; post-ARI b = -0.0012, p <.001), which held after adjusting for NH characteristics. Registered nurse hours (b = -0.0026, p <.001), licensed practical nurse hours (b = -0.0019, p <.001), facility chain membership (b = -0.0013, p <.01), and health inspection ratings (b = -0.0003, p >.01) were associated with decreased antipsychotic use. Post-ARI changes in associations between NH characteristics and antipsychotic use were small and not statistically significant. CONCLUSIONS: Decreases in antipsychotic use were associated with most NH characteristics, and associations persisted post-ARI. Further research is warranted to examine the interactions between ARI policy and NH characteristics on antipsychotic prescribing, as well as other NH factors, such as facility prescribing cultures and clinical specialty of staff. CLINICAL IMPLICATIONS: Decreases in monthly antipsychotic use were observed following the ARI. The decreases in monthly antipsychotic use were associated with most NH characteristics, and these associations persisted during the post-ARI period.

6.
Hum Brain Mapp ; 44(4): 1579-1592, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36440953

RESUMEN

This study aimed to investigate the influence of stroke lesions in predefined highly interconnected (rich-club) brain regions on functional outcome post-stroke, determine their spatial specificity and explore the effects of biological sex on their relevance. We analyzed MRI data recorded at index stroke and ~3-months modified Rankin Scale (mRS) data from patients with acute ischemic stroke enrolled in the multisite MRI-GENIE study. Spatially normalized structural stroke lesions were parcellated into 108 atlas-defined bilateral (sub)cortical brain regions. Unfavorable outcome (mRS > 2) was modeled in a Bayesian logistic regression framework. Effects of individual brain regions were captured as two compound effects for (i) six bilateral rich club and (ii) all further non-rich club regions. In spatial specificity analyses, we randomized the split into "rich club" and "non-rich club" regions and compared the effect of the actual rich club regions to the distribution of effects from 1000 combinations of six random regions. In sex-specific analyses, we introduced an additional hierarchical level in our model structure to compare male and female-specific rich club effects. A total of 822 patients (age: 64.7[15.0], 39% women) were analyzed. Rich club regions had substantial relevance in explaining unfavorable functional outcome (mean of posterior distribution: 0.08, area under the curve: 0.8). In particular, the rich club-combination had a higher relevance than 98.4% of random constellations. Rich club regions were substantially more important in explaining long-term outcome in women than in men. All in all, lesions in rich club regions were associated with increased odds of unfavorable outcome. These effects were spatially specific and more pronounced in women.


Asunto(s)
Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Femenino , Humanos , Masculino , Persona de Mediana Edad , Teorema de Bayes , Encéfalo , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/patología , Modelos Neurológicos
7.
Opt Express ; 31(26): 44328-44339, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-38178506

RESUMEN

We have developed a low-cost micro-diffuse reflectance infrared Fourier transform spectroscopic (micro-DRIFTS) setup for measuring the reflectance of small area diffuse samples. The system performance is characterized and then demonstrated on small area vertically aligned carbon nanotube (VACNT) samples. We find that our system can measure samples with a spatial resolution of approximately 140 µm with sensitivities of 10s of ppm in the 2 µm - 18 µm spectral window. Our uncertainty budget is presented along with how our measured reflectance can be equated to directional-hemispherical reflectance.

8.
Stroke ; 53(3): e66-e69, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34802251

RESUMEN

BACKGROUND AND PURPOSE: Although the US Black population has a higher incidence of stroke compared with the US White population, few studies have addressed Black-White differences in the contribution of vascular risk factors to the population burden of ischemic stroke in young adults. METHODS: A population-based case-control study of early-onset ischemic stroke, ages 15 to 49 years, was conducted in the Baltimore-Washington DC region between 1992 and 2007. Risk factor data was obtained by in-person interview in both cases and controls. The prevalence, odds ratio, and population-attributable risk percent (PAR%) of smoking, diabetes, and hypertension was determined among Black patients and White patients, stratified by sex. RESULTS: The study included 1044 cases and 1099 controls. Of the cases, 47% were Black patients, 54% were men, and the mean (±SD) age was 41.0 (±6.8) years. For smoking, the population-attributable risk percent were White men 19.7%, White women 32.5%, Black men 10.1%, and Black women 23.8%. For diabetes, the population-attributable risk percent were White men 10.5%, White women 7.4%, Black men 17.2%, and Black women 13.4%. For hypertension, the population-attributable risk percent were White men 17.2%, White women 19.3%, Black men 45.8%, and Black women 26.4%. CONCLUSIONS: Modifiable vascular risk factors account for a large proportion of ischemic stroke in young adults. Cigarette smoking was the strongest contributor to stroke among White patients while hypertension was the strongest contributor to stroke among Black patients. These results support early primary prevention efforts focused on smoking cessation and hypertension detection and treatment.


Asunto(s)
Negro o Afroamericano , Accidente Cerebrovascular Isquémico/epidemiología , Fumar/efectos adversos , Población Blanca , Adolescente , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Incidencia , Accidente Cerebrovascular Isquémico/etiología , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Adulto Joven
9.
Molecules ; 27(15)2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35897877

RESUMEN

The use of 2-pyridyl oximes in metal complexes chemistry has been extensively investigated in the last few decades as a fruitful source of species with interesting magnetic properties. In this work, the initial combination of pyridine-2-amidoxime (pyaoxH2) and 2-methyl pyridyl ketoxime (mpkoH) with isonicotinic acid (HINA) and 3,5-pyrazole dicarboxylic acid (H3pdc) has provided access to three new compounds, [Ni4(INA)2(pyaox)2(pyaoxH)2(DMF)2] (1), [Co5(mpko)6(mpkoH)2(OMe)2(H2O)](ClO4)6 (2), and [Co5(OH)(Hpdc)5(H2pdc)] (3). 1 displays a square-planar metal topology, being the first example that bears simultaneously HINA and pyaoxH2 in their neutral or ionic form. The neighbouring Ni4 units in 1 are held together through strong intermolecular hydrogen bonding interactions, forming a three-dimensional supramolecular framework. 2 and 3 are mixed-valent Co4IIICoII and Co2IIICoII3 compounds with a bowtie and trigonal bipyramidal metal topology, accordingly. Direct current and alternate current magnetic susceptibility studies revealed that the exchange interactions between the NiII ions in 1 are ferromagnetic (J = 1.79(4) cm-1), while 2 exhibits weak AC signals in the presence of a magnetic field. The syntheses, crystal structures, and magnetic properties of 1-3 are discussed in detail.


Asunto(s)
Complejos de Coordinación , Complejos de Coordinación/química , Cristalografía por Rayos X , Ligandos , Imanes , Modelos Moleculares , Oximas/química
10.
Stroke ; 52(10): 3184-3190, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34266309

RESUMEN

BACKGROUND AND PURPOSE: Few studies have examined the dose-response and temporal relationships between marijuana use and ischemic stroke while controlling for important confounders, including the amount of tobacco smoking. The purpose of our study was to address these knowledge gaps. METHODS: A population-based case-control study with 1090 cases and 1152 controls was used to investigate the relationship of marijuana use and early-onset ischemic stroke. Cases were first-ever ischemic stroke between the ages of 15 and 49 identified from 59 hospitals in the Baltimore-Washington region. Controls obtained by random digit dialing from the same geographic region were frequency-matched to cases by age, sex, region of residence and, except for the initial study phase, race. After excluding subjects with cocaine and other vasoactive substance use, the final study sample consisted of 751 cases and 813 controls. All participants underwent standardized interviews to characterize stroke risk factors and marijuana use. Unconditional logistic regression analysis was used to assess the relationships between marijuana use and risk of ischemic stroke, adjusting for age, sex, race, study phase, the amount of current tobacco smoking, current alcohol use, hypertension, and diabetes. RESULTS: After adjusting for other risk factors, including the amount of current tobacco smoking, marijuana use was not associated with ischemic stroke, regardless of the timing of use in relationship to the stroke, including ever use, use within 30 days, and use within 24 hours. There was a nonsignificant trend towards increased stroke risk among those who smoked marijuana at least once a week (odds ratio, 1.9 [95% CI, 0.8-4.9]). CONCLUSIONS: These analyses do not demonstrate an association between marijuana use and an increased risk of early-onset ischemic stroke, although statistical power was limited for assessing the association among very heavy users.


Asunto(s)
Accidente Cerebrovascular Isquémico/epidemiología , Fumar Marihuana/efectos adversos , Adolescente , Adulto , Edad de Inicio , Consumo de Bebidas Alcohólicas , Estudios de Casos y Controles , Diabetes Mellitus , Femenino , Humanos , Hipertensión/complicaciones , Accidente Cerebrovascular Isquémico/prevención & control , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Riesgo , Fumar Tabaco , Adulto Joven
11.
Org Biomol Chem ; 19(12): 2716-2724, 2021 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-33667287

RESUMEN

Ring-fused benzimidazolequinones are well-known anti-tumour agents, but dimeric ring-fused adducts are new. The alicyclic [1,2-a] ring-fused dimethoxybenzimidazole-benzimidazolequinone (DMBBQ) intermediate allows late-stage functionalization of bis-p-benzimidazolequinones. DMBBQs are chlorinated and brominated at the p-dimethoxybenzene site using nontoxic sodium halide and Oxone in HFIP/water. X-ray crystallography is used to rationalize site preference in terms of the discontinuity in conjugation in the DMBBQ system. Quinone formation occurs by increasing in situ halogen generation and water. Conversely, radical trifluoromethylation occurs at the quinone of the DMBBQ.

12.
Drug Dev Ind Pharm ; 47(2): 302-307, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33492999

RESUMEN

Amorphization is a well-established strategy to enhance the dissolution properties of poorly water-soluble drugs. However, the amorphous state is inherently unstable toward recrystallization. Coamorphous systems of a drug and a small-molecule excipient or of two complementary drugs often show an enhanced stability. Diabetes and hypertension are frequently coexistent. In this paper a study on the coamorphization of the poorly water-soluble antidiabetic drug gliclazide (glz) and the antihypertensive drug valsartan (val) is reported. Amorphous glz recrystallized after 1 d under ambient conditions, whereas coamorphous glz-val containing glz and val in a 1:1 or 1:2 molar ratio was stable for at least four months at 20 °C and 56% relative humidity. The dissolution rate of glz increased in the order crystalline glz < glz-val_1:1 < glz-val_1:2. Furthermore, ternary coamorphous systems of glz, val and an excipient were prepared; glz-val_1:1_PVP, glz-val_1:1_HPC, glz-val_1:1_ALM, glz-val_1:1_MCC (PVP = polyvinylpyrrolidone, HPC = hydroxypropyl cellulose, ALM = α-lactose monohydrate, MCC = microcrystalline cellulose). MCC and HPC did not affect the stability of the coamorphous system, while ALM promoted the recrystallization of glz in glz-val_1:1_ALM during storage and freshly prepared glz-val_1:1_PVP contained small amounts of crystalline glz. Glz-val_1:1_MCC showed enhanced dissolution properties compared to crystalline glz and glz-val_1:1 and is a viable fixed-dose formulation.


Asunto(s)
Gliclazida , Valsartán/química , Estabilidad de Medicamentos , Excipientes , Solubilidad , Valsartán/farmacología
13.
Food Qual Prefer ; 882021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32999533

RESUMEN

Vegetable intake is far below recommendations among African-American adolescents living in economically-underserved urban areas. While the National School Lunch Program (NSLP) helps overcome access barriers, vegetable intake remains challenging and novel interventions are required. A two-year, multi-phase, school-based intervention was conducted at an urban, economically-underserved, and predominantly African-American high school in Baltimore, Maryland to determine whether stakeholder-informed addition of spices and herbs to NSLP vegetables would increase intake. The stakeholder engagement phase included assessment of NSLP vegetable attitudes/preferences among 43 school stakeholders and subsequent student sensory testing. The second phase was conducted in the school cafeteria and consisted of eight weeks comparing student intake of typical vegetable recipes versus otherwise-identical recipes with spices and herbs. 4,570 student lunch plates were included in the vegetable intake comparison. Vegetable intake was measured by lunch tray plate waste. Willingness to try vegetables was assessed by the difference between plate waste and estimated mean vegetable served weight. Intake of typical vegetable recipes and vegetable recipes with spices and herbs was compared with student's t-test. Chi-square test was used to compare willingness to try vegetables. Total vegetable intake was 18.2% higher (8.22 grams per meal, p<0.0001) with spices and herbs than with typical recipes. There were no differences in trying vegetables with spices and herbs, although student-led advocacy was associated with increased trying vegetables with spices and herbs (78.8% with advocacy, 67.5% without advocacy, p<0.0001). The addition of spices and herbs to vegetables in the NSLP was feasible and associated with small increases in vegetable intake at an urban, economically-underserved, and predominantly African-American high school.

14.
Molecules ; 26(2)2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33477697

RESUMEN

The simultaneous use of 2-pyridyl oximes (pyridine-2 amidoxime, H2pyaox; 2-methyl pyridyl ketoxime, Hmpko) and 1,3,5-benzenetricarboxylic acid (H3btc) provided access to five new compounds, namely [Zn(H2btc)2(H2pyaox)2]•2H2O (1•2H2O), [Zn(Hbtc)(H2pyaox)2]n (2), [Cu(Hbtc)(H2pyaox)]n (3), [Cu(Hbtc)(HmpKo)]n (4) and [Cu2(Hbtc)2(Hmpko)2(H2O)2]•4H2O (5•4H2O). Among them, 3 is the first example of a metal-organic framework (MOF) containing H2pyaox. Its framework can be described as a 3-c uninodal net of hcb topology with the layers being parallel to the (1,0,1) plane. Furthermore, 3 is the third reported MOF based on a 2-pyridyl oxime in general. 2 and 4 are new members of a small family of coordination polymers containing an oximic ligand. 1-5 form 3D networks through strong intermolecular interactions. Dc magnetic susceptibility studies were carried out in a crystalline sample of 3 and revealed the presence of weak exchange interactions between the metal centres; the experimental data were fitted to a theoretical model with the fitting parameters being J = -0.16(1) cm-1 and g = 2.085(1). The isotropic g value was also confirmed by electronic paramagnetic resonance (EPR) spectroscopy. Reactivity studies were performed for 3 in the presence of metal ions; the reaction progress was studied and discussed for Fe(NO3)3 by the use of several characterization techniques, including single crystal X-ray crystallography and IR spectroscopy.


Asunto(s)
Complejos de Coordinación/química , Cobre/química , Estructuras Metalorgánicas/química , Oximas/química , Polímeros/química , Ácidos Tricarboxílicos/química , Zinc/química , Ligandos , Piridinas
15.
Stroke ; 51(11): 3356-3360, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32912094

RESUMEN

BACKGROUND AND PURPOSE: The genetic contribution to ischemic stroke may include rare- or low-frequency variants of high-penetrance and large-effect sizes. Analyses focusing on early-onset disease, an extreme-phenotype, and on the exome, the protein-coding portion of genes, may increase the likelihood of identifying such rare functional variants. To evaluate this hypothesis, we implemented a 2-stage discovery and replication design, and then addressed whether the identified variants also associated with older-onset disease. METHODS: Discovery was performed in UMD-GEOS Study (University of Maryland-Genetics of Early-Onset Stroke), a biracial population-based study of first-ever ischemic stroke cases 15 to 49 years of age (n=723) and nonstroke controls (n=726). All participants had prior GWAS (Genome Wide Association Study) and underwent Illumina exome-chip genotyping. Logistic-regression was performed to test single-variant associations with all-ischemic stroke and TOAST (Trial of ORG 10172 in Acute Stroke Treatment) subtypes in Whites and Blacks. Population level results were combined using meta-analysis. Gene-based aggregation testing and meta-analysis were performed using seqMeta. Covariates included age and gender, and principal-components for population structure. Pathway analyses were performed across all nominally associated genes for each stroke outcome. Replication was attempted through lookups in a previously reported meta-analysis of early-onset stroke and a large-scale stroke genetics study consisting of primarily older-onset cases. RESULTS: Gene burden tests identified a significant association with NAT10 in small-vessel stroke (P=3.79×10-6). Pathway analysis of the top 517 genes (P<0.05) from the gene-based analysis of small-vessel stroke identified several signaling and metabolism-related pathways related to neurotransmitter, neurodevelopmental notch-signaling, and lipid/glucose metabolism. While no individual SNPs reached chip-wide significance (P<2.05×10-7), several were near, including an intronic variant in LEXM (rs7549251; P=4.08×10-7) and an exonic variant in TRAPPC11 (rs67383011; P=5.19×10-6). CONCLUSIONS: Exome-based analysis in the setting of early-onset stroke is a promising strategy for identifying novel genetic risk variants, loci, and pathways.


Asunto(s)
Accidente Cerebrovascular Isquémico/genética , Adolescente , Adulto , Negro o Afroamericano , Edad de Inicio , Exoma/genética , Femenino , Redes Reguladoras de Genes , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Persona de Mediana Edad , Población Blanca , Adulto Joven
16.
Stroke ; 50(7): 1734-1741, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31177973

RESUMEN

Background and Purpose- We evaluated deep learning algorithms' segmentation of acute ischemic lesions on heterogeneous multi-center clinical diffusion-weighted magnetic resonance imaging (MRI) data sets and explored the potential role of this tool for phenotyping acute ischemic stroke. Methods- Ischemic stroke data sets from the MRI-GENIE (MRI-Genetics Interface Exploration) repository consisting of 12 international genetic research centers were retrospectively analyzed using an automated deep learning segmentation algorithm consisting of an ensemble of 3-dimensional convolutional neural networks. Three ensembles were trained using data from the following: (1) 267 patients from an independent single-center cohort, (2) 267 patients from MRI-GENIE, and (3) mixture of (1) and (2). The algorithms' performances were compared against manual outlines from a separate 383 patient subset from MRI-GENIE. Univariable and multivariable logistic regression with respect to demographics, stroke subtypes, and vascular risk factors were performed to identify phenotypes associated with large acute diffusion-weighted MRI volumes and greater stroke severity in 2770 MRI-GENIE patients. Stroke topography was investigated. Results- The ensemble consisting of a mixture of MRI-GENIE and single-center convolutional neural networks performed best. Subset analysis comparing automated and manual lesion volumes in 383 patients found excellent correlation (ρ=0.92; P<0.0001). Median (interquartile range) diffusion-weighted MRI lesion volumes from 2770 patients were 3.7 cm3 (0.9-16.6 cm3). Patients with small artery occlusion stroke subtype had smaller lesion volumes ( P<0.0001) and different topography compared with other stroke subtypes. Conclusions- Automated accurate clinical diffusion-weighted MRI lesion segmentation using deep learning algorithms trained with multi-center and diverse data is feasible. Both lesion volume and topography can provide insight into stroke subtypes with sufficient sample size from big heterogeneous multi-center clinical imaging phenotype data sets.


Asunto(s)
Isquemia Encefálica/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Accidente Cerebrovascular/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Macrodatos , Isquemia Encefálica/epidemiología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Aprendizaje Automático , Masculino , Persona de Mediana Edad , Redes Neurales de la Computación , Variaciones Dependientes del Observador , Fenotipo , Estudios Retrospectivos , Factores de Riesgo , Factores Socioeconómicos , Accidente Cerebrovascular/epidemiología
17.
J Org Chem ; 84(15): 9811-9818, 2019 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-31293163

RESUMEN

The reactivity of hydrogen peroxide and catalytic hydroiodic acid toward 3,6-dimethoxy-2-(cycloamino)anilines is tunable to give ring-fused benzimidazoles or 1,4,6,9-tetramethoxyphenazine in high yield. Mechanisms via a detected nitroso-intermediate are proposed for oxidative cyclization and the unexpected intermolecular displacement of the oxazine. An aqueous solution of molecular iodine is capable of the same transformations. Oxidative demethylation gave targeted benzimidazolequinones, including without cleavage of the incorporated oxetane.


Asunto(s)
Antineoplásicos/química , Bencimidazoles/química , Descubrimiento de Drogas , Éteres Cíclicos/química , Morfolinas/química , Fenazinas/química , Quinonas/química , Ácidos/química , Antineoplásicos/síntesis química , Bencimidazoles/síntesis química , Catálisis , Ciclización , Peróxido de Hidrógeno/química , Compuestos de Yodo/química , Estructura Molecular , Oxidación-Reducción , Fenazinas/síntesis química , Quinonas/síntesis química
18.
Ann Neurol ; 81(3): 383-394, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27997041

RESUMEN

OBJECTIVE: Genome-wide association studies (GWAS) have been successful at identifying associations with stroke and stroke subtypes, but have not yet identified any associations solely with small vessel stroke (SVS). SVS comprises one quarter of all ischemic stroke and is a major manifestation of cerebral small vessel disease, the primary cause of vascular cognitive impairment. Studies across neurological traits have shown that younger-onset cases have an increased genetic burden. We leveraged this increased genetic burden by performing an age-at-onset informed GWAS meta-analysis, including a large younger-onset SVS population, to identify novel associations with stroke. METHODS: We used a three-stage age-at-onset informed GWAS to identify novel genetic variants associated with stroke. On identifying a novel locus associated with SVS, we assessed its influence on other small vessel disease phenotypes, as well as on messenger RNA (mRNA) expression of nearby genes, and on DNA methylation of nearby CpG sites in whole blood and in the fetal brain. RESULTS: We identified an association with SVS in 4,203 cases and 50,728 controls on chromosome 16q24.2 (odds ratio [OR; 95% confidence interval {CI}] = 1.16 [1.10-1.22]; p = 3.2 × 10-9 ). The lead single-nucleotide polymorphism (rs12445022) was also associated with cerebral white matter hyperintensities (OR [95% CI] = 1.10 [1.05-1.16]; p = 5.3 × 10-5 ; N = 3,670), but not intracerebral hemorrhage (OR [95% CI] = 0.97 [0.84-1.12]; p = 0.71; 1,545 cases, 1,481 controls). rs12445022 is associated with mRNA expression of ZCCHC14 in arterial tissues (p = 9.4 × 10-7 ) and DNA methylation at probe cg16596957 in whole blood (p = 5.3 × 10-6 ). INTERPRETATION: 16q24.2 is associated with SVS. Associations of the locus with expression of ZCCHC14 and DNA methylation suggest the locus acts through changes to regulatory elements. Ann Neurol 2017;81:383-394.


Asunto(s)
Enfermedades de los Pequeños Vasos Cerebrales/genética , Cromosomas Humanos Par 16/genética , Estudio de Asociación del Genoma Completo , Accidente Cerebrovascular/genética , Dedos de Zinc/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Sitios Genéticos , Variación Genética , Humanos , Masculino , Persona de Mediana Edad , Accidente Vascular Cerebral Lacunar/genética
19.
Org Biomol Chem ; 16(22): 4108-4116, 2018 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-29774925

RESUMEN

The traditional thermal Mannich reaction is unsuitable for preparing polymerizable N-methylene amino substituted acrylamides and methacrylamides. Herein we provide a facile multi-gram high yield synthesis of these monomeric precursors to stimuli-responsive polymers by the addition of acrylamides and methacrylamides onto in situ generated or freshly isolated methylene Schiff base (iminium) salts. The X-ray crystal structure of the hydrated iminium salt, 1-(hydroxymethyl)azocan-1-ium chloride and monomer·HCl salt (N-[(azocan-1-yl)methyl]prop-2-enamide hydrochloride) is described.

20.
Beilstein J Org Chem ; 14: 1222-1228, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29977390

RESUMEN

A simple one-pot method for the microwave-assisted synthesis of substituted pyrazolo[1,5-a]pyrimidinones, a core scaffold in many bioactive and pharmaceutically relevant compounds, has been established. A variety of substituents was tolerated at the 2 and 5 positions, including functionalized aryls, heterocycles, and alkyl groups.

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