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1.
Phys Rev Lett ; 132(6): 062702, 2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38394565

RESUMEN

The cross section of the ^{13}C(α,n)^{16}O reaction is needed for nuclear astrophysics and applications to a precision of 10% or better, yet inconsistencies among 50 years of experimental studies currently lead to an uncertainty of ≈15%. Using a state-of-the-art neutron detection array, we have performed a high resolution differential cross section study covering a broad energy range. These measurements result in a dramatic improvement in the extrapolation of the cross section to stellar energies potentially reducing the uncertainty to ≈5% and resolving long standing discrepancies in higher energy data.

2.
Phys Rev Lett ; 130(21): 212701, 2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37295108

RESUMEN

The rate of the final step in the astrophysical αp process, the ^{34}Ar(α,p)^{37}K reaction, suffers from large uncertainties due to a lack of experimental data, despite having a considerable impact on the observable light curves of x-ray bursts and the composition of the ashes of hydrogen and helium burning on accreting neutron stars. We present the first direct measurement constraining the ^{34}Ar(α,p)^{37}K reaction cross section, using the Jet Experiments in Nuclear Structure and Astrophysics gas jet target. The combined cross section for the ^{34}Ar,Cl(α,p)^{37}K,Ar reaction is found to agree well with Hauser-Feshbach predictions. The ^{34}Ar(α,2p)^{36}Ar cross section, which can be exclusively attributed to the ^{34}Ar beam component, also agrees to within the typical uncertainties quoted for statistical models. This indicates the applicability of the statistical model for predicting astrophysical (α,p) reaction rates in this part of the αp process, in contrast to earlier findings from indirect reaction studies indicating orders-of-magnitude discrepancies. This removes a significant uncertainty in models of hydrogen and helium burning on accreting neutron stars.


Asunto(s)
Helio , Hidrógeno , Modelos Estadísticos , Neutrones
3.
Phys Rev Lett ; 125(6): 062501, 2020 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-32845657

RESUMEN

Precise antineutrino measurements are very sensitive to proper background characterization. We present an improved measurement of the ^{13}C(α,n)^{16}O reaction cross section which constitutes significant background for large ν[over ¯] detectors. We greatly improve the precision and accuracy by utilizing a setup that is sensitive to the neutron energies while making measurements of the excited state transitions via secondary γ-ray detection. Our results shows a 54% reduction in the background contributions from the ^{16}O(3^{-},6.13 MeV) state used in the KamLAND analysis.

4.
Dis Esophagus ; 33(12)2020 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-32607539

RESUMEN

Volumetric laser endomicroscopy (VLE) has been shown to improve detection of early neoplasia in Barrett's esophagus (BE). However, diagnostic performance using histopathology-correlated VLE regions of interest (ROIs) has not been adequately studied. We evaluated the diagnostic accuracy of VLE assessors for identification of early BE neoplasia in histopathology-correlated VLE ROIs. In total, 191 ROIs (120 nondysplastic and 71 neoplastic) from 50 BE patients were evaluated in a random order using a web-based module. All ROIs contained histopathology correlations enabled by VLE laser marking. Assessors were blinded to endoscopic BE images and histology. ROIs were first scored as nondysplastic or neoplastic. Level of confidence was assigned to the predicted diagnosis. Outcome measures were: (i) diagnostic performance of VLE assessors for identification of BE neoplasia in all VLE ROIs, defined as accuracy, sensitivity, and specificity; (ii) diagnostic performance of VLE assessors for only high level of confidence predictions; and (iii) interobserver agreement. Accuracy, sensitivity, and specificity for BE neoplasia identification were 79% (confidence interval [CI], 75-83), 75% (CI, 71-79), and 81% (CI, 76-86), respectively. When neoplasia was identified with a high level of confidence, accuracy, sensitivity, and specificity were 88%, 83%, and 90%, respectively. The overall strength of interobserver agreement was fair (k = 0.29). VLE assessors can identify BE neoplasia with reasonable diagnostic accuracy in histopathology-correlated VLE ROIs, and accuracy is enhanced when BE neoplasia is identified with high level of confidence. Future work should focus on renewed VLE image reviewing criteria and real-time automatic assessment of VLE scans.


Asunto(s)
Esófago de Barrett , Neoplasias Esofágicas , Esofagoscopía , Humanos , Rayos Láser , Microscopía Confocal
5.
Dis Esophagus ; 32(9)2019 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-31037293

RESUMEN

Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291.


Asunto(s)
Esófago de Barrett/diagnóstico por imagen , Pautas de la Práctica en Medicina/estadística & datos numéricos , Tomografía de Coherencia Óptica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Esófago de Barrett/patología , Esófago de Barrett/terapia , Biopsia , Toma de Decisiones Clínicas , Sistemas de Computación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sistema de Registros , Tomografía de Coherencia Óptica/estadística & datos numéricos , Estados Unidos
6.
Dis Esophagus ; 32(3)2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30541019

RESUMEN

The 4-quadrant forceps biopsy (FB) protocol for identifying Barrett's esophagus (BE) and esophageal dysplasia (ED) suffers from poor sensitivity due to significant sampling error. We investigated the benefit of wide-area transepithelial sampling with 3-dimensional computer-assisted analysis (WATS) used adjunctively to the combination of random and targeted FB in the detection of ED, and as a secondary outcome, BE. In this multicenter prospective trial, community endoscopists at 21 sites utilized WATS as an adjunct to both targeted and random FB in patients undergoing BE screening and surveillance. Investigators alternated taking FB and WATS samples first. WATS specimens were analyzed at CDx Diagnostics (Suffern, NY) while FB samples were analyzed by each site's regular pathologists. Data were de-identified and then aggregated for analysis. Of 12,899 patients enrolled, FB identified 88 cases of ED, and WATS detected an additional 213 cases missed by FB. These 213 cases represented an absolute increase of 1.65%, raising the yield from 0.68% to 2.33%. Adding WATS to FB increased the overall detection of ED by 242% (95% CI: 191%-315%). Fewer than 61 patients needed to be tested with WATS to identify an additional case of ED. The combination of random and targeted FB identified 1,684 cases of BE, and WATS detected an additional 2,570 BE cases. The absolute incremental yield of adding WATS to FB is 19.9%, increasing the rate of detection from 13.1% to 33%. Adding WATS to FB increased the overall detection of BE by 153% (95% CI: 144-162%). The number needed to test with WATS in order to detect an additional case of BE was 5. Whether FB or WATS was done first did not impact the results. In this study, comprised of the largest series of patients evaluated with WATS, adjunctive use of the technique with targeted and random FB markedly improved the detection of both ED and BE. These results underscore the shortcomings of FB in detecting BE-associated neoplasia, which can potentially impact the management and clinical outcomes of these patients.


Asunto(s)
Esófago de Barrett/diagnóstico , Diagnóstico por Computador/estadística & datos numéricos , Enfermedades del Esófago/diagnóstico , Imagenología Tridimensional/estadística & datos numéricos , Lesiones Precancerosas/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia/métodos , Biopsia/estadística & datos numéricos , Diagnóstico por Computador/métodos , Errores Diagnósticos , Mucosa Esofágica/diagnóstico por imagen , Mucosa Esofágica/patología , Esófago/diagnóstico por imagen , Esófago/patología , Femenino , Humanos , Imagenología Tridimensional/métodos , Masculino , Tamizaje Masivo/métodos , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Instrumentos Quirúrgicos , Adulto Joven
7.
Dis Esophagus ; 30(9): 1-6, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28859359

RESUMEN

Abdominal obesity is associated with gastroesophageal reflux disease (GERD) and Barrett's esophagus (BE). Increased body mass index (BMI) and waist-to-hip ratio (WHR) have been associated with BE. Abdominal diameter index (ADI, sagittal abdominal diameter divided by thigh circumference) was previously shown to be a more accurate predictor of incident cardiovascular disease compared to other measurements. Our aim is to examine whether abdominal diameter index was a more accurate predictor of prevalent BE compared to other anthropometric measurements. We conducted a case-control study of patients presenting to our institution. Our study population was consecutive Caucasian men with a known history of BE, and we recruited control patients who had GERD without BE. Both groups completed a questionnaire about demographics, smoking, and medications and underwent a series of anthropometric body measurements using standardized measuring tools. BMI, waist-to-hip ratio, and abdominal diameter index were calculated. Thirty-one BE patients and 27 control patients were recruited. The BE cohort were older and had a higher rate of hiatal hernia. The mean abdominal diameter index for patients with BE was 0.65 ± 0.07 and without BE was 0.60 ± 0.07 (p = 0.01). The predictive value of abdominal diameter index was analyzed using a receiver-operator characteristic (ROC) curve and was a more powerful predictor of BE than waist-to-hip ratio or BMI (AUROC = 0.70 vs. 0.60 vs. 0.52, respectively). Using a cut-point abdominal diameter index value of 0.60, abdominal diameter index had a sensitivity of 77.4% and a specificity of 63.0% for the presence of BE. When controlling for age, smoking status, and BMI, an abdominal diameter index ≥0.60 was a significant independent risk factor for BE (OR = 5.7, 95% CI = 1.29-25.4). In this pilot study, the abdominal diameter index appears to be a more powerful predictor of the presence of BE than BMI and waist-to-hip ratio and remained the only significant predictor of BE in multivariate analysis. We propose further validation of abdominal diameter index before inclusion in future prediction tools for BE.


Asunto(s)
Esófago de Barrett/diagnóstico , Índice de Masa Corporal , Diámetro Abdominal Sagital , Relación Cintura-Cadera , Adulto , Anciano , Área Bajo la Curva , Estudios de Casos y Controles , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Valor Predictivo de las Pruebas , Curva ROC , Factores de Riesgo , Encuestas y Cuestionarios
8.
J Neuroendocrinol ; 29(6)2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28561903

RESUMEN

The underlying hypothalamic neurocircuitry by which metabolism and feeding regulates reproductive function has been well-studied in the rodent; however, recent data have demonstrated significant neuroanatomical differences in the human brain. The present study had three objectives, centred on arcuate nucleus neuropeptides regulating feeding and reproduction: (i) to characterise coexpression patterns in the female nonhuman primate; (ii) to establish whether these neuronal populations make potential contacts with gonadotophin-releasing hormone (GnRH) neurones; and (iii) to determine whether these contacts differ between the low and high GnRH-releasing states of pre-puberty and adulthood, respectively. Female nonhuman primates have several coexpression patterns of hypothalamic neuropeptides that differ from those reported in rodents. Cocaine- and amphetamine-regulated transcript (CART) is not coexpressed with pro-opiomelanocortin but instead with neuropeptide Y (NPY). CART is also expressed in a subpopulation of kisspeptin cells in the nonhuman primate, similar to observations in humans but diverging from findings in rodents. Very few GnRH-expressing neurones received close appositions from double-labelled kisspeptin/CART fibres; however, both single-labelled kisspeptin and CART fibres were in frequent apposition with GnRH neurones, with no differences between prepubertal and adult animals. NPY/agouti-related peptide (AgRP) coexpressing fibres contacted significantly more GnRH neurones in prepubertal animals than adults, consistent with increased NPY and AgRP mRNA observed in prepubertal animals. The findings of the present study detail significant differences in arcuate nucleus neuropeptide coexpression in the monkey compared to the rodent and are consistent with the hypothesis that arcuate nucleus NPY/AgRP neurones play an inhibitory role in controlling GnRH neuronal regulation in the prepubertal primate.


Asunto(s)
Núcleo Arqueado del Hipotálamo/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Macaca mulatta , Factores de Edad , Proteína Relacionada con Agouti/metabolismo , Animales , Recuento de Células , Femenino , Kisspeptinas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Neuropéptido Y/metabolismo
9.
Bone Marrow Transplant ; 51(4): 573-80, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26726945

RESUMEN

Pneumocystis jiroveci pneumonia (PJP) is associated with high morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Little is known about PJP infections after HSCT because of the rarity of disease given routine prophylaxis. We report the results of a Center for International Blood and Marrow Transplant Research study evaluating the incidence, timing, prophylaxis agents, risk factors and mortality of PJP after autologous (auto) and allogeneic (allo) HSCT. Between 1995 and 2005, 0.63% allo recipients and 0.28% auto recipients of first HSCT developed PJP. Cases occurred as early as 30 days to beyond a year after allo HSCT. A nested case cohort analysis with supplemental data (n=68 allo cases, n=111 allo controls) revealed that risk factors for PJP infection included lymphopenia and mismatch after HSCT. After allo or auto HSCT, overall survival was significantly poorer among cases vs controls (P=0.0004). After controlling for significant variables, the proportional hazards model revealed that PJP cases were 6.87 times more likely to die vs matched controls (P<0.0001). We conclude PJP infection is rare after HSCT but is associated with high mortality. Factors associated with GVHD and with poor immune reconstitution are among the risk factors for PJP and suggest that protracted prophylaxis for PJP in high-risk HSCT recipients may improve outcomes.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Pneumocystis carinii , Neumonía por Pneumocystis , Aloinjertos , Autoinjertos , Femenino , Humanos , Incidencia , Masculino , Neumonía por Pneumocystis/etiología , Neumonía por Pneumocystis/mortalidad , Neumonía por Pneumocystis/prevención & control , Factores de Riesgo
10.
J Aquat Anim Health ; 27(3): 152-5, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26198857

RESUMEN

The ability of the anesthetics metomidate hydrochloride and tricaine methanesulfonate (MS-222) to mitigate the cortisol stress response of Channel Catfish Ictalurus punctatus was evaluated during a 10-min confinement stress. The cortisol concentrations of Channel Catfish anesthetized in metomidate hydrochloride remained consistent throughout the 10-min exposure; however, for fish anesthetized with MS-222 and nonanesthetized fish, cortisol concentrations were approximately 7- and 22-fold higher, respectively, than the baseline concentrations. While both anesthetics reduced cortisol concentrations relative to those of nonanesthetized fish, these results suggest that MS-222 is an appropriate anesthetic to use during the initial 5 min of sedation and that metomidate hydrochloride is appropriate for longer periods of sedation.


Asunto(s)
Aminobenzoatos/farmacología , Etomidato/análogos & derivados , Hidrocortisona/sangre , Ictaluridae/metabolismo , Estrés Fisiológico/efectos de los fármacos , Aminobenzoatos/efectos adversos , Anestésicos/efectos adversos , Anestésicos/farmacología , Animales , Etomidato/efectos adversos , Etomidato/farmacología , Ictaluridae/sangre
11.
Appl Opt ; 54(16): 5094-101, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-26192670

RESUMEN

In this work, we present the excitation/emission strategy, experimental setup, and results of an implementation of krypton tagging velocimetry (KTV). KTV is performed as follows: (i) seed a base flow with krypton; (ii) photosynthesize metastable krypton atoms with a frequency-doubled dye laser to form the tagged tracer; (iii) record the translation of the tagged metastable krypton by imaging the laser-induced fluorescence (LIF) that is produced with an additional dye laser. The principle strength of KTV, relative to other tagging velocimetry techniques, is the use of a chemically inert tracer. KTV results are presented for an underexpanded jet of three mixtures of varying Kr/N2 concentration. It is demonstrated that KTV can be used in gas mixtures of relatively low krypton mole fraction (0.5% Kr/99.5% N2), and the KTV data from that experiment are found to be in good agreement with an empirical fit found in the literature. We find that KTV is useful to perform instantaneous velocity measurements with metastable krypton as a chemically inert, dilute, long-lifetime tracer in gas-phase flows.

12.
Phys Rev Lett ; 114(21): 212501, 2015 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-26066430

RESUMEN

The Galactic 1.809-MeV γ-ray signature from the ß decay of ^{26g}Al is a dominant target of γ-ray astronomy, of which a significant component is understood to originate from massive stars. The ^{26g}Al(p,γ)^{27}Si reaction is a major destruction pathway for ^{26g}Al at stellar temperatures, but the reaction rate is poorly constrained due to uncertainties in the strengths of low-lying resonances in ^{27}Si. The ^{26g}Al(d,p)^{27}Al reaction has been employed in inverse kinematics to determine the spectroscopic factors, and hence resonance strengths, of proton resonances in ^{27}Si via mirror symmetry. The strength of the 127-keV resonance is found to be a factor of 4 higher than the previously adopted upper limit, and the upper limit for the 68-keV resonance has been reduced by an order of magnitude, considerably constraining the ^{26g}Al destruction rate at stellar temperatures.

13.
J Econ Entomol ; 107(3): 1201-5, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25026683

RESUMEN

A durable termite bait containing 0.5% noviflumuron was evaluated for physical durability, retention of active ingredient, consumption by termites, and toxicity to termites over 5 yr in field studies at locations in Indiana, Mississippi, and South Carolina. Plots in Indiana and Mississippi included both natural rainfall and irrigated plots, while plots in South Carolina received only natural rainfall. Samples collected every 3 mo for the first 4 yr were evaluated for consumption with a 7 d no-choice bioassay using Reticulitermes flavipes (Kollar). Consumption and toxicity of 5 yr samples were evaluated in similar bioassays conducted for 42 d. Durable baits received from field sites had some cracking, and a small amount of external flaking, but no major deterioration based on visual observation. There were no significant differences in noviflumuron concentration over the 5-yr period and no trend toward reduced concentrations of noviflumuron over time. Consumption of aged durable baits over 4 yr was variable, but termites usually consumed more aged durable bait than fresh durable bait and the differences were frequently significant. There were some exceptions, but termites consumed significantly more fresh durable bait than aged durable bait in only 4% of observations. When 5 yr samples were evaluated, consumption was lowest for fresh durable bait and termites consumed significantly more aged durable bait from irrigated plots in Indiana and from both natural and irrigated plots in Mississippi than fresh durable bait. Survival of termites fed blank durable bait was significantly higher than that for termites fed any of the baits containing noviflumuron and there were no significant differences in survival among the noviflumuron durable baits. Our results suggest that the bait would be durable for at least 5 yr and possibly longer under most environmental conditions.


Asunto(s)
Benzamidas , Hidrocarburos Fluorados , Control de Insectos/métodos , Insecticidas , Isópteros , Animales , Celulosa , Indiana , Control de Insectos/instrumentación , Mississippi , Estaciones del Año , Suelo , South Carolina , Factores de Tiempo
14.
Phys Rev Lett ; 112(17): 172701, 2014 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-24836240

RESUMEN

Single-neutron states in (133)Sn and (209)Pb, which are analogous to single-electron states outside of closed atomic shells in alkali metals, were populated by the ((9)Be, (8)Be) one-neutron transfer reaction in inverse kinematics using particle-γ coincidence spectroscopy. In addition, the s(1/2) single-neutron hole-state candidate in (131)Sn was populated by ((9)Be, (10)Be). Doubly closed-shell (132)Sn (radioactive) and (208)Pb (stable) beams were used at sub-Coulomb barrier energies of 3 MeV per nucleon. Level energies, γ-ray transitions, absolute cross sections, spectroscopic factors, asymptotic normalization coefficients, and excited-state lifetimes are reported and compared with shell-model expectations. The results include a new transition and precise level energy for the 3p(1/2) candidate in (133)Sn, new absolute cross sections for the 1h(9/2) candidate in (133)Sn and 3s(1/2) candidate in (131)Sn, and new lifetimes for excited states in (133)Sn and (209)Pb. This is the first report on excited-state lifetimes of (133)Sn, which allow for a unique test of the nuclear shell model and (132)Sn double-shell closure.

15.
Int J Sports Med ; 34(10): 868-72, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23559410

RESUMEN

Despite the vigorous nature of rock/pop drumming, there are no precise data on the energy expenditure of this activity. The aim of this study was to quantify the energy cost of rock/pop drumming. Fourteen male drummers (mean±SD; age 27±8 yrs.) completed an incremental drumming test to establish the relationship between energy expenditure and heart rate for this activity and a ramped cycle ergometer test to exhaustion as a criterion measure for peak values (oxygen uptake and heart rate). During live concert performance heart rate was continuously measured and used to estimate energy expenditure (from the energy expenditure vs. heart rate data derived from the drumming test). During concert performance, estimated energy expenditure (mean±SD) was 623±168 kcal.h⁻¹ (8.1±2.2 METs) during performances of 38.6±15.6 min, and drummers achieved a peak heart rate of 186±16 b.min⁻¹. During the drumming test participants attained 78.7±8.3% of the cycle ergometer peak oxygen uptake. Rock/pop drumming represents a relatively high-intensity form of physical activity and as such involves significant energy expenditure. Rock/pop drumming should be considered as a viable alternative to more traditional forms of physical activity.


Asunto(s)
Metabolismo Energético/fisiología , Actividad Motora/fisiología , Música , Adulto , Prueba de Esfuerzo , Voluntarios Sanos , Frecuencia Cardíaca , Humanos , Masculino , Consumo de Oxígeno
16.
J Endocrinol ; 217(2): 207-13, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23420316

RESUMEN

Chronic high caloric intake has contributed to the increased prevalence of pediatric obesity and related morbidities. Most overweight or obese children, however, do not present with frank metabolic disease but rather insulin resistance or subclinical precursors. The innate immune system plays a role in the pathophysiology of type 2 diabetes but how it contributes to early metabolic dysfunction in children on chronic high-fat diet (HFD) is unclear. We hypothesize that such inflammation is present in the pancreas of children and is associated with early insulin resistance. We used nonhuman primate (NHP) juveniles exposed to chronic HFD as a model of early pediatric metabolic disease to demonstrate increased pancreatic inflammatory markers before the onset of significant obesity or glucose dysregulation. Pancreata from 13-month-old Japanese macaques exposed to a HFD from in utero to necropsy were analyzed for expression of cytokines and islet-associated macrophages. Parameters from an intravenous glucose tolerance test were correlated with cytokine expression. Before significant glucose dysregulation, the HFD cohort had a twofold increase in interleukin 6 (IL6), associated with decreased first-phase insulin response and a sexually dimorphic (male) increase in IL1ß correlating with increased fasting glucose levels. The number of islet-associated macrophages was also increased. Pancreata from juvenile NHP exposed to HFD have increased inflammatory markers and evidence of innate immune infiltration before the onset of significant obesity or glucose dysregulation. Given the parallel development of metabolic disease between humans and NHPs, these findings have strong relevance to the early metabolic disease driven by a chronic HFD in children.


Asunto(s)
Resistencia a la Insulina/fisiología , Islotes Pancreáticos/patología , Macrófagos/patología , Pancreatitis/patología , Pancreatitis/fisiopatología , Animales , Glucemia/metabolismo , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Femenino , Interleucina-1beta/sangre , Interleucina-6/sangre , Macaca , Masculino , Pancreatitis/etiología , Factores Sexuales
17.
Phys Rev Lett ; 109(17): 172501, 2012 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-23215181

RESUMEN

Recent calculations suggest that the rate of neutron capture by (130)Sn has a significant impact on late-time nucleosynthesis in the r process. Direct capture into low-lying bound states is expected to be significant in neutron capture near the N=82 closed shell, so r-process reaction rates may be strongly impacted by the properties of neutron single particle states in this region. In order to investigate these properties, the (d,p) reaction has been studied in inverse kinematics using a 630 MeV beam of (130)Sn (4.8 MeV/u) and a (CD(2))(n) target. An array of Si strip detectors, including the Silicon Detector Array and an early implementation of the Oak Ridge Rutgers University Barrel Array, was used to detect reaction products. Results for the (130)Sn(d, p)(131)Sn reaction are found to be very similar to those from the previously reported (132)Sn(d, p)(133)Sn reaction. Direct-semidirect (n,γ) cross section calculations, based for the first time on experimental data, are presented. The uncertainties in these cross sections are thus reduced by orders of magnitude from previous estimates.

18.
Phys Rev Lett ; 108(19): 192701, 2012 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-23003029

RESUMEN

The best examples of halo nuclei, exotic systems with a diffuse nuclear cloud surrounding a tightly bound core, are found in the light, neutron-rich region, where the halo neutrons experience only weak binding and a weak, or no, potential barrier. Modern direct-reaction measurement techniques provide powerful probes of the structure of exotic nuclei. Despite more than four decades of these studies on the benchmark one-neutron halo nucleus 11Be, the spectroscopic factors for the two bound states remain poorly constrained. In the present work, the 10Be(d,​p) reaction has been used in inverse kinematics at four beam energies to study the structure of 11Be. The spectroscopic factors extracted using the adiabatic model were found to be consistent across the four measurements and were largely insensitive to the optical potential used. The extracted spectroscopic factor for a neutron in an nℓj=2s(1/2) state coupled to the ground state of 10Be is 0.71(5). For the first excited state at 0.32 MeV, a spectroscopic factor of 0.62(4) is found for the halo neutron in a 1p(1/2) state.

19.
Neurology ; 78(14): 1069-78, 2012 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-22442431

RESUMEN

OBJECTIVE: To report the long-term safety and efficacy results from CAMMS223 comparing alemtuzumab with interferon ß-1a in early, active relapsing-remitting multiple sclerosis (RRMS). What are the long-term effects of alemtuzumab treatment, received 36 to 48 months previously, on relapse and disability in early, active RRMS? This study provides evidence of the effectiveness of alemtuzumab in reducing the relapse rate and accumulation of disability compared with interferon ß-1a (IFNß-1a) through extended follow-up (up to 60 months from baseline). METHODS: Of 334 patients originally randomized, 198 participated in the extension phase (151 [68%] alemtuzumab and 47 [42%] IFNß-1a). Disability, relapses, and safety were assessed as in the original study period. Efficacy outcomes were analyzed from baseline of the original trial period to 60 months. Safety data extended beyond 60 months. RESULTS: Over 5 years, alemtuzumab lowered the risk of sustained accumulation of disability by 72% and the rate of relapse by 69% compared with IFNß-1a (both p < 0.0001). The annualized relapse rate from baseline to month 60 was 0.11 for alemtuzumab and 0.35 for IFNß-1a. Complete safety follow-up reflected 988 and 376 person-years for alemtuzumab and IFNß-1a patients, respectively. Serious infections were seen in 7% of alemtuzumab patients and 3% of IFNß-1a patients, and thyroid disorders were seen in 30% of alemtuzumab patients vs 4% of IFNß-1a patients. Immune thrombocytopenia occurred in 3% of alemtuzumab patients and 0.9% of IFNß-1a patients during the initial study period; no additional events were reported during the extension phase. One alemtuzumab patient developed Goodpasture disease 39 months after the second annual cycle of alemtuzumab. CONCLUSIONS: Through extended follow-up, alemtuzumab remained significantly more efficacious than IFNß-1a, with a safety profile consistent with previous reports. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that alemtuzumab is more effective than interferon ß-1a in reducing relapses and disability in patients with RRMS in a long-term follow-up of a rater-blinded, randomized clinical trial with 59.5% of patients participating in the extended follow-up period.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Interferón beta/uso terapéutico , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/fisiopatología , Adulto , Alemtuzumab , Femenino , Estudios de Seguimiento , Humanos , Interferón beta-1a , Masculino , Esclerosis Múltiple Recurrente-Remitente/inmunología , Método Simple Ciego , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
20.
Diabetes Obes Metab ; 13(9): 832-40, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21554521

RESUMEN

AIMS: The effects of insulins detemir (Det) and glargine (Glar) on endogenous glucose production (EGP) and net hepatic glucose output (NHGO) were compared. METHODS: Arteriovenous difference and tracer ([3-(3) H]glucose) techniques were employed during a two-step hyperinsulinemic euglycaemic clamp in conscious dogs (6 groups, n = 5-6/group). After equilibration and basal sampling (0-120 min), somatostatin was infused and basal glucagon was replaced intraportally. Det or Glar was infused via portal vein (Po), peripheral vein (IV), or bilateral carotid and vertebral arteries (H) at 0.1 and 0.3 mU/kg/min (low Insulin; Glar vs. Det, respectively, 120-420 min) and 4× the low insulin rate (high insulin; 420-540 min). RESULTS: NHGO and EGP were suppressed and glucose R(d) and infusion rate were stimulated similarly by Det and Glar at both Low and high insulin with each infusion route. Non-esterified fatty acid (NEFA) concentrations during low insulin were 202 ± 37 versus 323 ± 75 µM in DetPo and GlarPo (p < 0.05) and 125 ± 39 versus 263 ± 48 µM in DetIV and GlarIV, respectively (p < 0.05). In DetH versus GlarH, pAkt/Akt (1.7 ± 0.2 vs. 1.0 ± 0.2) and pSTAT3/STAT3 (1.4 ± 0.2 vs. 1.0 ± 0.1) were significantly increased in the liver but not in the hypothalamus. CONCLUSIONS: Det and Glar have similar net effects on acute regulation of hepatic glucose metabolism in vivo regardless of delivery route. Portal and IV detemir delivery reduces circulating NEFA to a greater extent than glargine, and head detemir infusion enhances molecular signalling in the liver. These findings indicate a need for further examination of Det's central and hepatic effects.


Asunto(s)
Glucemia/efectos de los fármacos , Sistema Nervioso Central/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Hipoglucemiantes/farmacología , Insulina/análogos & derivados , Hígado/metabolismo , Animales , Sistema Nervioso Central/efectos de los fármacos , Sistema Nervioso Central/patología , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/patología , Perros , Técnica de Clampeo de la Glucosa , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación , Insulina/farmacología , Insulina Detemir , Insulina Glargina , Insulina de Acción Prolongada , Hígado/efectos de los fármacos , Hígado/patología
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