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1.
Appl Opt ; 62(35): 9353-9360, 2023 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-38108707

RESUMEN

An optical system for multichannel coupling of laser arrays to polymer waveguide array probes with a single biconvex lens is developed. The developed cylindrical module with 13 mm and 20 mm in diameter and length, respectively, enables coupling of eight individual optical channels using an aspheric lens. Specific coupling with crosstalk below -13d B for each channel and quasi-uniform coupling over all channels is achieved for a waveguide array with 100 µm lateral facet pitch at the incoupling site. The polymer waveguide technology allows for tapering of the lateral waveguide pitch to 25 µm toward the tip of the flexible waveguide array. SU-8 and PMMA are used as the waveguide core and cladding, respectively. The optical coupling module is designed as a prototype for preclinical evaluation of optical neural stimulators.

2.
Zootaxa ; 5301(2): 219-245, 2023 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-37518564

RESUMEN

The scientific life of Robert P. Higgins was devoted to meiofauna, microscopically small animals living in aquatic sediments from the intertidal to hadal depths worldwide. He focused on the taxonomy, life-history, and ecology of the marine taxa Kinorhyncha, Tardigrada, and Priapulida and co-discovered the phylum Loricifera. He improved the methods for studying meiofauna and contributed significantly to spreading knowledge about these animals. Aspects of his life are described and lists of his publications, taxa described, contributions to science, and honours received are provided.

3.
Zool Stud ; 59: e18, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33262842

RESUMEN

The Afrotropical tardigrade fauna is insufficiently studied, and consequently its diversity in this region is severely underestimated. Ongoing sampling in the Udzungwa Mountains, Morogoro Region of Tanzania has revealed a new representative of the genus Echiniscus C.A.S. Schultze, 1840 (Echiniscidae). Echiniscus tantulus sp. nov. belongs to the spinulosus group, but it stands out from other members of this speciose Echiniscus clade by having a heteromorphic sculpture of the dorsal plates and an uncommonly stable body appendage configuration A-C-C d -D d -E. The new species is characteristic by being equipped with long dorsal spines and very short lateral spicules, which so far have been found only in one other species of the group, Echiniscus spinulosus (Doyère, 1840). An updated checklist of Tanzanian Echiniscidae is provided, incorporating recent advances in their classification.

4.
J Eur Acad Dermatol Venereol ; 34(3): 533-541, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31599476

RESUMEN

BACKGROUND: Psoriasis is associated with metabolic, liver and cardiovascular comorbidity. Secukinumab, a fully human monoclonal antibody that selectively neutralizes interleukin-17A, has shown significant and sustained efficacy in the treatment of moderate to severe psoriasis. OBJECTIVES: This was an exploratory post hoc analysis of pooled data from three phase 3 studies in plaque psoriasis patient populations. The objective was to show the course of metabolic and liver parameters under secukinumab, etanercept or placebo treatment over time. A further objective was to assess the impact of selected comorbidities and metabolic characteristics on high-sensitivity C-reactive protein (hs-CRP), as a surrogate marker of systemic inflammation. METHODS: Data from the phase 3 randomized controlled trials [FIXTURE (NCT01358578), ERASURE (NCT01365455) and SCULPTURE (NCT01406938); n = 3010] were included in this analysis. Patients were treated with secukinumab 150 mg or 300 mg, placebo or etanercept 50 mg (FIXTURE only) as active comparator. A set of metabolic and liver parameters was longitudinally assessed over 52 weeks. Multivariate regression analyses assessed the impact of selected comorbidities and metabolic characteristics on hs-CRP levels at baseline and under treatment. RESULTS: Secukinumab treatment reduced hs-CRP levels. Body weight and uric acid levels tended to decrease over 52 weeks with secukinumab. Secukinumab showed a neutral effect on fasting plasma glucose, lipid parameters and liver enzymes. Psoriatic arthritis, metabolic syndrome, obesity, impaired glucose metabolism, and hyperuricemia were each associated with increased hs-CRP levels at baseline. Concomitant obesity attenuated the decline in hs-CRP under treatment. CONCLUSIONS: These analyses suggest neutral to favourable long-term trends in metabolic and liver parameters under secukinumab treatment. Metabolic comorbidities were associated with increased hs-CRP levels, reflecting the role of systemic inflammatory processes in their pathophysiology.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Etanercept/farmacología , Etanercept/uso terapéutico , Hígado/efectos de los fármacos , Hígado/metabolismo , Psoriasis/tratamiento farmacológico , Psoriasis/metabolismo , Adulto , Femenino , Humanos , Estudios Longitudinales , Masculino , Índice de Severidad de la Enfermedad
5.
J Dermatolog Treat ; 31(5): 531-534, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31179792

RESUMEN

Background: Adiponectin is an adipocyte-secreted protein potentially relevant in the context of cardiometabolic comorbidity of psoriasis patients.Objective: This post-hoc analysis aimed to assess the impact of obesity, metabolic syndrome, psoriasis severity and treatment with secukinumab/etanercept on adiponectin.Methods: Three phase III trials in moderate to severe plaque psoriasis were included. Correlations of Psoriasis Area and Severity Index (PASI), body mass index (BMI), and associated comorbidity with adiponectin levels as well as the impact of secukinumab, etanercept, and placebo were analyzed.Results: Data of 3010 patients were included of whom 71.2% had a BMI >25. Adiponectin levels were significantly higher in patients with lower BMI (r = -0.23; p < .0001) and in patients without metabolic syndrome compared to patients with higher BMI and with metabolic syndrome. PASI score was negatively associated with adiponectin levels (r = -0.065; p = .0004). However, the correlation was extremely weak and thus clinically irrelevant. During treatment with secukinumab or etanercept over 52 weeks adiponectin levels remained stable.Conclusion: Metabolic syndrome and BMI are key determinants of adiponectin levels in psoriasis patients. Psoriasis severity and anti-psoriatic treatment had no relevant impact on adiponectin levels.


Asunto(s)
Adiponectina/análisis , Psoriasis/patología , Adulto , Anticuerpos Monoclonales Humanizados/uso terapéutico , Biomarcadores/análisis , Índice de Masa Corporal , Ensayos Clínicos Fase II como Asunto , Comorbilidad , Etanercept/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Efecto Placebo , Psoriasis/tratamiento farmacológico , Índice de Severidad de la Enfermedad
6.
Chirurg ; 90(10): 851-857, 2019 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-30783725

RESUMEN

BACKGROUND: The aim of this study was to investigate the effectiveness of the treatment of osteoid osteomas (OO) by radiofrequency ablation (RFA). In particular, the recurrence rate and the improvement in the quality of life as assessed by the reduction of pain intensity were evaluated. METHODS: Retrospective analysis of 26 patients after RFA of an OO and prospective analysis of 14 patients using a self-developed quality of life questionnaire. The questionnaire, the electronic patient file and the histopathological findings were processed. RESULTS: An average of 22 months passed between the first onset of complaints and the causative treatment by RFA. After RFA, there was a significant reduction in pain symptoms and thus an increase in the quality of life. These results confirm that RFA from OO is a safe and efficient treatment procedure. DISCUSSION: In order to avoid long-term conservative treatment attempts and to reduce effects on the musculoskeletal system, a timely RFA of OO should be performed after diagnosis.


Asunto(s)
Neoplasias Óseas , Osteoma Osteoide , Calidad de Vida , Ablación por Radiofrecuencia/métodos , Neoplasias Óseas/cirugía , Ablación por Catéter , Humanos , Recurrencia Local de Neoplasia , Osteoma Osteoide/cirugía , Estudios Prospectivos , Estudios Retrospectivos , Resultado del Tratamiento
7.
J Endocrinol Invest ; 42(8): 979-986, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30674009

RESUMEN

PURPOSE: To examine the association of epicardial and pericardial fat volume (EFV, PFV) with cardiovascular risk factors and kidney function in Native Americans of southwestern heritage with youth and early adult onset type 2 diabetes mellitus (T2DM) versus healthy controls. METHODS: Using computed tomography, we quantified EFV and PFV in 149 Native Americans (92 women, 57 men), 95 of which had T2DM (38 diagnosed prior to age 20 years). Duration of T2DM, mean carotid arterial mass (AM), coronary artery calcification (CAC), IL-6, and estimated glomerular filtration rate eGFRcr(CKD-EPI) were measured. RESULTS: EFV and PFV were associated with BMI (r = 0.37, p < 0.0001; r = 0.26, p = 0.001) and did not differ between onset age-groups and controls (p > 0.05). EFV was associated with AM only in controls (r = 0.51, p < 0.0001). After adjustment for BMI, T2DM duration, HbA1C, age, and sex, EFV was a predictor of CAC and IL-6 concentrations in early adult onset T2DM (ß = 0.05 ± 0.02 cm3, p = 0.03; ß = 0.05 ± 0.01 pg/ml/cm3, p = 0.002). EFV and PFV were independent predictors of reduced eGFRcr(CKD-EPI) in the youth onset T2DM group (ß = -0.3 ± 0.08 ml/min/cm3, p = 0.001; ß = -0.25 ± 0.05 ml/min/cm3, p < 0.0001). CONCLUSIONS: Epicardial fat volume may be a risk factor for heart disease in individuals with early adult onset T2DM and a predictor of decreased kidney function in individuals with youth onset T2DM.


Asunto(s)
Tejido Adiposo/patología , Biomarcadores/análisis , Enfermedad de la Arteria Coronaria/diagnóstico , Diabetes Mellitus Tipo 2/complicaciones , Pericardio/patología , Insuficiencia Renal/diagnóstico , Adolescente , Adulto , Edad de Inicio , Estudios de Casos y Controles , Niño , Enfermedad de la Arteria Coronaria/etiología , Mapeo Epicárdico , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Pronóstico , Insuficiencia Renal/etiología , Factores de Riesgo , Adulto Joven
8.
J Hosp Infect ; 100(3): e40-e46, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30026008

RESUMEN

BACKGROUND: Increased antimicrobial resistance has been observed among many bacteria leading to treatment failures in human and veterinary medicine. Disinfection is a prerequisite for infection control and prevention in healthcare settings. Chlorine compounds are cost-effective and accessible worldwide. AIM: To determine the efficacy of sodium hypochlorite (NaOCl) against multidrug-resistant Gram-negative bacteria (MDR-GNB). METHODS: Minimum inhibitory concentrations (MICs) were determined using broth macro-dilution. Bactericidal efficacy was measured by qualitative and quantitative suspension tests followed by practical tests without mechanical action on stainless steel carriers. The guidelines of the German Association for Applied Hygiene were followed. FINDINGS: Results varied remarkably depending on the method. MICs were 0.1% or 0.2% NaOCl. Qualitative suspension tests revealed up to 500-fold lower bactericidal concentrations. Pseudomonas aeruginosa (P = 0.0025) was significantly less susceptible in these tests whereas quantitative suspension tests revealed no significant differences between strains (P > 0.05). Practical tests determined bactericidal concentrations of 0.8-0.32% NaOCl at 1 min of contact and even lower concentrations for longer contact times. At 1 min, five Klebsiella were significantly less susceptible (P = 0.0124), whereas the lower susceptibility of P. aeruginosa was not confirmed. Organic load inhibited bactericidal activity significantly, whereas contact time had a marginal effect. Differing test results underline that MIC determination and qualitative suspension tests may be insufficient approaches to evaluate bacterial susceptibility or resistance. CONCLUSION: NaOCl efficiently reduced Pseudomonas aeruginosa, Acinetobacter spp., and Klebsiella spp., most notably in the absence of organic matter. Strain- and species-specific differences in susceptibility were noticed, but in general MDR-GNB revealed no higher tolerance to NaOCl.


Asunto(s)
Acinetobacter/efectos de los fármacos , Desinfectantes/farmacología , Klebsiella/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Hipoclorito de Sodio/farmacología , Farmacorresistencia Bacteriana Múltiple , Humanos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos
9.
Geobiology ; 16(3): 237-251, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29569335

RESUMEN

Fossil derivatives of isorenieratene, an accessory pigment in brown-colored green sulfur bacteria, are often used as tracers for photic zone anoxia through Earth's history, but their diagenetic behavior is still incompletely understood. Here, we assess the preservation of isorenieratene derivatives in organic-rich shales (1.5-8.4 wt.% TOC) from two Lower Jurassic anoxic systems (Bächental oil shale, Tyrol, Austria; Posidonia Shale, Baden-Württemberg, Germany). Bitumens and kerogens were investigated using catalytic hydropyrolysis (HyPy), closed-system hydrous pyrolysis (in gold capsules), gas chromatography-mass spectrometry (GC-MS) and gas chromatography combustion isotope ratio-mass spectrometry (GC-C-IRMS). Petrography and biomarkers indicate a syngenetic relationship between bitumens and kerogens. All bitumens contain abundant isorenieratane, diverse complex aromatized isorenieratene derivatives, and a pseudohomologous series of 2,3,6-trimethyl aryl isoprenoids. In contrast, HyPy and mild closed-system hydrous pyrolysis of the kerogens yielded only minor amounts of these compounds. Given the overall low maturity of the organic matter (below oil window), it appears that isorenieratene and its abundant derivatives from the bitumen had not been incorporated into the kerogens. Accordingly, sulfur cross-linking, the key mechanism for sequestration of functionalized lipids into kerogens in anoxic systems, was not effective in the Jurassic environments studied. We explain this by (i) early cyclization/aromatization and (ii) hydrogenation reactions that have prevented effective sulfurization. In addition, (iii) sulfide was locally removed via anoxygenic photosynthesis and efficiently trapped by the reaction with sedimentary iron, as further indicated by elevated iron contents (4.0-8.7 wt.%) and the presence of abundant pyrite aggregates in the rock matrix. Although the combined processes have hampered the kerogen incorporation of isorenieratene and its derivatives, they may have promoted the long-term preservation of these biomarkers in the bitumen fraction via early defunctionalization. This particular taphonomy of aromatic carotenoids has to be considered in studies of anoxic iron-rich environments (e.g., the Proterozoic ocean).


Asunto(s)
Carotenoides/metabolismo , Chlorobi/química , Fósiles , Sedimentos Geológicos/química , Hierro/metabolismo , Fenoles/metabolismo , Pigmentos Biológicos/metabolismo , Austria , Alemania , Hipoxia , Análisis Espectral
10.
Dent Mater ; 34(3): 494-507, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29395474

RESUMEN

OBJECTIVE: To estimate the fatigue resistance of a new translucent zirconia material in comparison to lithium disilicate for 3-unit fixed partial dentures (FPDs). METHODS: Eighteen 3-unit FPDs (replacement of first upper molar) with a connector size of 4mm×4mm were dry milled with a five-axis milling machine (Zenotec Select, Wieland, Germany) using discs made of a new translucent zirconia material (IPS e.max ZirCAD MT, Ivoclar Vivadent). Another 9 FPDs with a reduced connector size (3mm×4mm) were milled. The zirconia FPDs were sintered at 1500°C. For a comparison, 9 FPDs were made of IPS e.max Press, using the same dimensions. These IPS e.max Press FPDs were ground from a wax disc (Wieland), invested and pressed at 920°C. All FPDs were glazed twice. The FPDs were adhesively luted to PMMA dies with Multilink Automix. Dynamic cyclic loading was carried out on the molar pontic using Dyna-Mess testing machines (Stolberg, Germany) with 2×106 cycles at 2Hz in water (37°C). Two specimens per group and load were subjected to decreasing load levels (at least 4) until the two specimens no longer showed any failures. Another third specimen was subjected to this load to confirm the result. All the specimens were evaluated under a stereo microscope (20× magnification). The number of cycles reached before observing a failure, and their dependence on the load and on the material, were modeled, using a Weibull model. This made it possible to estimate the fatigue resistance as the maximum load for which one would observe less than 1% failure after 2×106 cycles. In addition to the experimental study, Finite Element Modeling (FEM) simulations were conducted to predict the force to failure for IPS e.max ZirCAD MT and IPS e.max Press with a reduced cross-section of the connectors. RESULTS: The failure mode of the zirconia FPDs was mostly the fracture of the distal connector, whereas the failure mode of the lithium disilicate FPDs observed to be the fracture of the connectors or multiple cracks of the pontic. The fatigue resistance with 1% fracture probability was estimated to be 488N for the IPS e.max ZirCAD MT FPDs (453N for repeated test), 365N for IPS e.max ZirCAD MT FPDs with reduced connector size and 286N for the e.max Press FPDs. All three IPS e.max ZirCAD groups statistically performed significantly better than IPS e.max Press (p<0.001). On the other hand, no significant difference could be established between the two IPS e.max ZirCAD MT3 groups with a 4mm×4mm connector size (p>0.05). The allowable maximum principal stress (σmax) which did not lead to failure during fatigue testing for IPS e.max ZirCAD MT3 was calculated between 208MPa and 223MPa for FPDs with 4mm×4mm connectors for 2×106 cycles. This value could also be verified for the FPDs of the same material with 3mm×4mm connectors. On the other hand fatigue strength in terms of σmax at 2×106 cycles of IPS e.max Press was calculated to be between 78 and 90MPa. SIGNIFICANCE: The fatigue resistance of the translucent zirconia 3-unit FPDs was about 60-70% higher than that of the lithium disilicate 3-unit FPDs, which may justify their use for molar replacements, provided that a minimal connector size of 4mm×4mm is observed. Even with a limited number of specimens (n=9) per group it was possible to statistically differentiate between the tested groups.


Asunto(s)
Cerámica/química , Fracaso de la Restauración Dental , Diseño de Dentadura , Dentadura Parcial Fija , Porcelana Dental/química , Análisis del Estrés Dental , Análisis de Elementos Finitos , Ensayo de Materiales , Polimetil Metacrilato
11.
Radiat Prot Dosimetry ; 179(3): 291-298, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29253239

RESUMEN

The purpose of this study was to assess the occupational radiation exposure arising from positron emission tomography combined with X-ray computed tomography (PET/CT) procedures. From 2009 through the end of 2014, in a team of six technologists, personal dosimetry was performed using electronic personal dosemeters and film badge dosemeters. The technologists registered the separate exposure after each PET/CT operational step, which included radiopharmaceutical arrival, dispensing in individual syringes, injection and patient positioning.From the total of 3024 PET/CT procedures, 2142 were available for analysis. The personal dose equivalent for the technologists performing PET/CT ranged from 11.5 nSv/MBq to 23.8 nSv/MBq. Whole-body radiation dose originated mainly from radiopharmaceutical injection (41.5%) and patient positioning (51.1%). The sources of occupational exposure were successfully identified for PET/CT procedures. Record keeping using on-site occupational dosimetry is a useful tool for exposure optimisation.


Asunto(s)
Fluorodesoxiglucosa F18 , Implementación de Plan de Salud , Exposición Profesional/análisis , Evaluación de Resultado en la Atención de Salud , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Traumatismos por Radiación/prevención & control , Radiofármacos , Humanos , Estudios Prospectivos , Dosis de Radiación , Protección Radiológica
13.
J Phys Condens Matter ; 29(26): 264001, 2017 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-28557803

RESUMEN

We study gadolinium thin films as a model system for ferromagnets with negative thermal expansion. Ultrashort laser pulses heat up the electronic subsystem and we follow the transient strain via ultrafast x-ray diffraction. In terms of a simple Grueneisen approach, the strain is decomposed into two contributions proportional to the thermal energy of spin and phonon subsystems. Our analysis reveals that upon femtosecond laser excitation, phonons and spins can be driven out of thermal equilibrium for several nanoseconds.

14.
Int J Obes (Lond) ; 41(3): 458-466, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27916985

RESUMEN

BACKGROUND: Body weight and adiposity are heritable traits. To date, it remains unknown whether obesity-associated brain structural alterations are under a similar level of genetic control. METHODS: For this study, we utilized magnetic resonance imaging data from the Human Connectome Project. Voxel-based morphometry was used to investigate associations between body mass index (BMI) and regional gray matter volume (GMV) in a sample of 875 young adults with a wide BMI range (386 males/489 females; age 28.8±3.7 years; BMI 26.6±5.3 kg m-2) that included 86 pairs of monozygotic twins and 82 pairs of dizygotic twins. Twin data were analyzed by applying the additive genetic, common environmental and residual effects model to determine heritability of brain regions that were associated with BMI. RESULTS: We observed positive associations between BMI and GMV in the ventromedial prefrontal cortex and the right cerebellum and widespread negative associations within the prefrontal cortex, cerebellum, temporal lobes and distinct subcortical structures. Varying degrees of heritability were found for BMI-associated brain regions, with the highest heritability estimates for cerebellar GMV and subcortical structures. CONCLUSIONS: These data indicate that brain regions associated with obesity are subject to differing levels of genetic control and environmental influences. Specific brain regions with high heritability might represent an inherent vulnerability factor for obesity.


Asunto(s)
Encéfalo/patología , Imagen por Resonancia Magnética , Obesidad/genética , Obesidad/patología , Adiposidad , Adulto , Femenino , Sustancia Gris/anatomía & histología , Sustancia Gris/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Neuroimagen , Obesidad/fisiopatología , Fenotipo , Carácter Cuantitativo Heredable , Gemelos Dicigóticos , Gemelos Monocigóticos
15.
Phys Rev Lett ; 117(10): 107403, 2016 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-27636494

RESUMEN

We present an optically induced remanent photostriction in BiFeO_{3}, resulting from the photovoltaic effect, which is used to modify the ferromagnetism of Ni film in a hybrid BiFeO_{3}/Ni structure. The 75% change in coercivity in the Ni film is achieved via optical and nonvolatile control. This photoferromagnetic effect can be reversed by static or ac electric depolarization of BiFeO_{3}. Hence, the strain dependent changes in magnetic properties are written optically, and erased electrically. Light-mediated straintronics is therefore a possible approach for low-power multistate control of magnetic elements relevant for memory and spintronic applications.

16.
Struct Dyn ; 3(5): 054302, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27679803

RESUMEN

We present a temperature and fluence dependent Ultrafast X-Ray Diffraction study of a laser-heated antiferromagnetic dysprosium thin film. The loss of antiferromagnetic order is evidenced by a pronounced lattice contraction. We devise a method to determine the energy flow between the phonon and spin system from calibrated Bragg peak positions in thermal equilibrium. Reestablishing the magnetic order is much slower than the cooling of the lattice, especially around the Néel temperature. Despite the pronounced magnetostriction, the transfer of energy from the spin system to the phonons in Dy is slow after the spin-order is lost.

17.
Int J Obes (Lond) ; 40(9): 1360-8, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27121248

RESUMEN

BACKGROUND/OBJECTIVES: Prader-Willi syndrome (PWS) is a type of human genetic obesity that may give us information regarding the physiology of non-syndromic obesity. The objective of this study was to investigate the functional correlates of hunger and satiety in individuals with PWS in comparison with healthy controls with obesity, hypothesizing that we would see significant differences in activation in the left dorsolateral prefrontal cortex (DLPFC) based on prior findings. SUBJECTS/METHODS: This study compared the central effects of food consumption in nine individuals with PWS (7 men, 2 women; body fat 35.3±10.0%) and seven controls (7 men; body fat 28.8±7.6%), matched for percentage body fat. H2(15)O-PET (positron emission tomography) scans were performed before and after consumption of a standardized liquid meal to obtain quantitative measures of regional cerebral blood flow (rCBF), a marker of neuronal activity. RESULTS: Compared with obese controls, PWS showed altered (P<0.05 family-wise error cluster-level corrected; voxelwise P<0.001) rCBF before and after meal consumption in multiple brain regions. There was a significant differential rCBF response within the left DLPFC after meal ingestion with decreases in DLPFC rCBF in PWS; in controls, DLPFC rCBF tended to remain unchanged. In more liberal analyses (P<0.05 family-wise error cluster-level corrected; voxelwise P<0.005), rCBF of the right orbitofrontal cortex (OFC) increased in PWS and decreased in controls. In PWS, ΔrCBF of the right OFC was associated with changes in appetite ratings. CONCLUSIONS: The pathophysiology of eating behavior in PWS is characterized by a paradoxical meal-induced deactivation of the left DLPFC and activation in the right OFC, brain regions implicated in the central regulation of eating behavior.


Asunto(s)
Periodo Posprandial , Síndrome de Prader-Willi/fisiopatología , Corteza Prefrontal/fisiopatología , Adulto , Mapeo Encefálico , Circulación Cerebrovascular , Conducta Alimentaria , Femenino , Neuroimagen Funcional , Humanos , Imagen por Resonancia Magnética , Masculino , Comidas , Síndrome de Prader-Willi/epidemiología , Recompensa , Saciedad , Respuesta de Saciedad
18.
Int J Obes (Lond) ; 40(5): 754-60, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26499440

RESUMEN

BACKGROUND/OBJECTIVES: In small studies, a thrifty human phenotype, defined by a greater 24-hour energy expenditure (EE) decrease with fasting, is associated with less weight loss during caloric restriction. In rodents, models of diet-induced obesity often have a phenotype including a reduced EE and decreased core body temperature. We assessed whether a thrifty human phenotype associates with differences in core body temperature or body composition. SUBJECTS/METHODS: Data for this cross-sectional analysis were obtained from 77 individuals participating in one of two normal physiology studies while housed on our clinical research unit. Twenty-four-hour EE using a whole-room indirect calorimeter and 24-h core body temperature were measured during 24 h each of fasting and 200% overfeeding with a diet consisting of 50% carbohydrates, 20% protein and 30% fat. Body composition was measured by dual X-ray absorptiometry. To account for the effects of body size on EE, changes in EE were expressed as a percentage change from 24-hour EE (%EE) during energy balance. RESULTS: A greater %EE decrease with fasting correlated with a smaller %EE increase with overfeeding (r=0.27, P=0.02). The %EE decrease with fasting was associated with both fat mass and abdominal fat mass, even after accounting for covariates (ß=-0.16 (95% CI: -0.26, -0.06) %EE per kg fat mass, P=0.003; ß=-0.0004 (-0.0007, -0.00004) %EE kg(-1) abdominal fat mass, P=0.03). In men, a greater %EE decrease in response to fasting was associated with a lower 24- h core body temperature, even after adjusting for covariates (ß=1.43 (0.72, 2.15) %EE per 0.1 °C, P=0.0003). CONCLUSIONS: Thrifty individuals, as defined by a larger EE decrease with fasting, were more likely to have greater overall and abdominal adiposity as well as lower core body temperature consistent with a more efficient metabolism.


Asunto(s)
Adiposidad/fisiología , Composición Corporal/fisiología , Temperatura Corporal/fisiología , Metabolismo Energético/fisiología , Fenotipo , Absorciometría de Fotón , Tejido Adiposo , Adulto , Arizona , Restricción Calórica , Estudios Transversales , Ayuno/fisiología , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Termogénesis
19.
Phys Rev Lett ; 115(19): 195502, 2015 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-26588396

RESUMEN

Phonons are often regarded as delocalized quasiparticles with certain energy and momentum. The anharmonic interaction of phonons determines macroscopic properties of the solid, such as thermal expansion or thermal conductivity, and a detailed understanding becomes increasingly important for functional nanostructures. Although phonon-phonon scattering processes depicted in simple wave-vector diagrams are the basis of theories describing these macroscopic phenomena, experiments directly accessing these coupling channels are scarce. We synthesize monochromatic acoustic phonon wave packets with only a few cycles to introduce nonlinear phononics as the acoustic counterpart to nonlinear optics. Control of the wave vector, bandwidth, and consequently spatial extent of the phonon wave packets allows us to observe nonlinear phonon interaction, in particular, second harmonic generation, in real time by wave-vector-sensitive Brillouin scattering with x-rays and optical photons.

20.
Curr Biol ; 25(15): 2000-6, 2015 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-26212884

RESUMEN

Despite rapid advances in the study of metazoan evolutionary history [1], phylogenomic analyses have so far neglected a number of microscopic lineages that possess a unique combination of characters and are thus informative for our understanding of morphological evolution. Chief among these lineages are the recently described animal groups Micrognathozoa and Loricifera, as well as the two interstitial "Problematica" Diurodrilus and Lobatocerebrum [2]. These genera show a certain resemblance to Annelida in their cuticle and gut [3, 4]; however, both lack primary annelid characters such as segmentation and chaetae [5]. Moreover, they show unique features such as an inverted body-wall musculature or a novel pharyngeal organ. This and their ciliated epidermis have led some to propose relationships with other microscopic spiralians, namely Platyhelminthes, Gastrotricha, and in the case of Diurodrilus, with Micrognathozoa [6, 7]-lineages that are grouped by some analyses into "Platyzoa," a clade whose status remains uncertain [1, 8-11]. Here, we assess the interrelationships among the meiofaunal and macrofaunal members of Spiralia using 402 orthologs mined from genome and transcriptome assemblies of 90 taxa. Lobatocerebrum and Diurodrilus are found to be deeply nested members of Annelida, and unequivocal support is found for Micrognathozoa as the sister group of Rotifera. Analyses using site-heterogeneous substitution models further recover a lophophorate clade and position Loricifera + Priapulida as sister group to the remaining Ecdysozoa. Finally, with several meiofaunal lineages branching off early in the diversification of Spiralia, the emerging concept of a microscopic, acoelomate, direct-developing ancestor of Spiralia is reviewed.


Asunto(s)
Evolución Biológica , Invertebrados/clasificación , Invertebrados/genética , Filogenia , Animales , Evolución Molecular , Invertebrados/anatomía & histología , Rotíferos/anatomía & histología , Rotíferos/clasificación , Rotíferos/genética
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