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1.
Nat Commun ; 13(1): 7743, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36522338

RESUMEN

The second Venus flyby of the BepiColombo mission offer a unique opportunity to make a complete tour of one of the few gas-dynamics dominated interaction regions between the supersonic solar wind and a Solar System object. The spacecraft pass through the full Venusian magnetosheath following the plasma streamlines, and cross the subsolar stagnation region during very stable solar wind conditions as observed upstream by the neighboring Solar Orbiter mission. These rare multipoint synergistic observations and stable conditions experimentally confirm what was previously predicted for the barely-explored stagnation region close to solar minimum. Here, we show that this region has a large extend, up to an altitude of 1900 km, and the estimated low energy transfer near the subsolar point confirm that the atmosphere of Venus, despite being non-magnetized and less conductive due to lower ultraviolet flux at solar minimum, is capable of withstanding the solar wind under low dynamic pressure.

2.
Nat Commun ; 13(1): 7390, 2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36450728

RESUMEN

Mercury's southern inner magnetosphere is an unexplored region as it was not observed by earlier space missions. In October 2021, BepiColombo mission has passed through this region during its first Mercury flyby. Here, we describe the observations of SERENA ion sensors nearby and inside Mercury's magnetosphere. An intermittent high-energy signal, possibly due to an interplanetary magnetic flux rope, has been observed downstream Mercury, together with low energy solar wind. Low energy ions, possibly due to satellite outgassing, were detected outside the magnetosphere. The dayside magnetopause and bow-shock crossing were much closer to the planet than expected, signature of a highly eroded magnetosphere. Different ion populations have been observed inside the magnetosphere, like low latitude boundary layer at magnetopause inbound and partial ring current at dawn close to the planet. These observations are important for understanding the weak magnetosphere behavior so close to the Sun, revealing details never reached before.

4.
Anal Bioanal Chem ; 414(1): 675-689, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34651209

RESUMEN

The application of Ca isotopic analysis in biomedical studies has great potential to identify changes in Ca metabolism and bone metabolism. Reliable measurement of Ca isotope-amount ratios is challenging considering limited Ca amounts and significant procedural blank levels. In this study, Ca purification was performed using the DGA Resin, optimized for low procedural blanks and separation of Ca from matrix elements and isobaric interferences (Na, Mg, K, Ti, Fe, Ba), while maintaining quasi-quantitative recoveries which are sufficient since a 42Ca-48Ca double-spike (DS) was applied. Ca isotopic analysis was performed using multicollector thermal ionization mass spectrometry (MC TIMS). The obtained procedural Ca blank of ≤10 ng enables processing of limited Ca amounts down to 670 ng. Data reduction of the measured Ca isotope-amount ratios was performed using an in-house developed software solving the DS algorithm. Data quality was improved by extension of equilibration time of the sample-DS mixture and implementation of a normalization strategy for raw isotopic data. The reported δ(44Ca/40Ca)NIST SRM 915a of NIST SRM 915a processed as a sample was found to be 0.01 ‰ ± 0.08 ‰ (2 SD, n = 15). Ca isotope-amount ratios of the reference material NIST SRM 1400 (bone ash), NIST SRM 1486 (bone meal), GBW07601 (human hair), and IAPSO (seawater) were in good agreement within uncertainty with literature data. Novel data on additional reference materials for biological tissues (hair) is presented, which might indicate a potential fractionation of Ca incorporated into hair tissue when compared to the blood pool.


Asunto(s)
Fraccionamiento Químico , Isótopos , Cabello/química , Humanos , Isótopos/análisis , Espectrometría de Masas/métodos
6.
Space Sci Rev ; 217(1): 11, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33487762

RESUMEN

The ESA-JAXA BepiColombo mission to Mercury will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric particle dynamics at Mercury as well as their interactions with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for ion and neutral particle detection aboard the MPO. It comprises four independent sensors: ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA is managed by a System Control Unit located inside the ELENA box. In the present paper the scientific goals of this suite are described, and then the four units are detailed, as well as their major features and calibration results. Finally, the SERENA operational activities are shown during the orbital path around Mercury, with also some reference to the activities planned during the long cruise phase.

7.
Sci Total Environ ; 707: 135219, 2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-31869611

RESUMEN

Recent studies suggested the use of the isotopic composition of Zn as a possible tracer for anthropogenic Zn emissions. Nevertheless, studies mainly focused on sampling areas of a few km2 with well-characterized anthropogenic Zn emissions. In contrast, this study focused on analyzing a large sample set of water and sediment samples taken throughout the course of the Elbe River, a large, anthropogenically impacted river system located in Central Europe. The primary objective was to evaluate the use of the isotopic composition of Zn to trace anthropogenic Zn emission on a large regional scale. In total 18 water and 26 surface sediment samples were investigated, covering the complete course of over 700 km of the German Elbe between the German/Czech border and the German North Sea, including six tributaries. Stable isotope abundance ratios of Zn were assessed by multi-collector inductively coupled plasma mass spectrometry (MC ICP-MS) in water filtrates (<0.45 µm) and total digests of the sieved surface sediment fraction (<63 µm) after analyte/matrix separation using Bio-Rad AG MP-1 resin via a micro-column approach and application of a 64Zn/67Zn double spike. Measured isotopic compositions of δ66Zn/64ZnIRMM-3702 ranged from -0.10 ‰ to 0.32 ‰ for sediment samples, and from -0.51 ‰ to 0.45 ‰ for water samples. In comparison to historical data some tributaries still feature high mass fractions of anthropogenic Zn (e.g. Mulde, Triebisch) combined with δ66Zn/64ZnIRMM-3702 values higher than the lithogenic background. The dissolved δ66Zn/64ZnIRMM-3702 values showed a potential correlation with pH. Our results indicate that biogeochemical processes like absorption may play a key role in natural Zn isotopic fractionation making it difficult to distinguish between natural and anthropogenic processes.

8.
Phys Rev Lett ; 120(6): 062503, 2018 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-29481255

RESUMEN

A precision mass investigation of the neutron-rich titanium isotopes ^{51-55}Ti was performed at TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). The range of the measurements covers the N=32 shell closure, and the overall uncertainties of the ^{52-55}Ti mass values were significantly reduced. Our results conclusively establish the existence of the weak shell effect at N=32, narrowing down the abrupt onset of this shell closure. Our data were compared with state-of-the-art ab initio shell model calculations which, despite very successfully describing where the N=32 shell gap is strong, overpredict its strength and extent in titanium and heavier isotones. These measurements also represent the first scientific results of TITAN using the newly commissioned multiple-reflection time-of-flight mass spectrometer, substantiated by independent measurements from TITAN's Penning trap mass spectrometer.

9.
Int J Cosmet Sci ; 39(6): 580-588, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28699157

RESUMEN

OBJECTIVE: Organosiloxanes are prevalent in personal care products (PCPs) due to the desired properties they impart in the usage and application of such products. However, the European Chemical Agency (ECHA) has recently published restriction proposals on the amount of two cyclic siloxanes, octamethylcyclotetrasiloxane (D4) and decamethylcyclotetrasiloxane (D5), allowed in wash off products such as shampoos and conditioners which are discharged down the drain during consumer use. This legislation will require that reliable analytical methods are available for manufacturers and government agencies to use in documenting compliance with the restrictions. This article proposes a simple analytical method to enable accurate measurement of these compounds down to the circa 0.1 weight per cent level in PCPs. METHODS: Although gas chromatography methods are reported in the literature for quantitation of D4 and D5 in several matrices including PCPs, the potential for generation of false positives due to contamination, co-elution and in situ generation of cyclic volatile methylsiloxanes (cVMS) is always present and needs to be controlled. This report demonstrates the applicability of using a combination of emulsion break, liquid-liquid extraction and silylation sample preparation followed by GC-FID analysis as a suitable means of analysing PCPs for specific cVMS. RESULTS: The reliability and limitations of such methodology were demonstrated through several round-robin studies conducted in the laboratories of a consortium of silicone manufacturers. In addition, this report presents examples of false positives encountered during development of the method and presents a comparative analysis between this method and a published QuEChERS sample preparation procedure to illustrate the potential for generation of false positives when an inappropriate approach is applied to determination of cVMS in personal care products. CONCLUSION: This report demonstrates that an approach to determine cVMS levels in personal care products is to perform an emulsion break on the sample, isolate the non-polar phase from the emulsion break and treat with a silylation reagent to abate potential in situ formation of cyclics during the course of GC-FID analysis. Round-robin studies conducted in laboratories representing multiple siloxane manufacturers demonstrated the reliability of the GC-FID method when measuring cVMS in PCPs down to circa 0.1%.


Asunto(s)
Cromatografía de Gases/métodos , Cosméticos/química , Siloxanos/análisis , Reproducibilidad de los Resultados , Volatilización
10.
Phys Rev Lett ; 116(7): 072501, 2016 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-26943530

RESUMEN

The atomic mass relations among the mass triplet ^{96}Zr, ^{96}Nb, and ^{96}Mo have been determined by means of high-precision mass measurements using the JYFLTRAP mass spectrometer at the IGISOL facility of the University of Jyväskylä. We report Q values for the ^{96}Zr single and double ß decays to ^{96}Nb and ^{96}Mo, as well as the Q value for the ^{96}Nb single ß decay to ^{96}Mo, which are Q_{ß}(^{96}Zr)=163.96(13), Q_{ßß}(^{96}Zr)=3356.097(86), and Q_{ß}(^{96}Nb)=3192.05(16) keV. Of special importance is the ^{96}Zr single ß-decay Q value, which has never been determined directly. The single ß decay, whose main branch is fourfold unique forbidden, is an alternative decay path to the ^{96}Zr ßß decay, and its observation can provide one of the most direct tests of the neutrinoless ßß-decay nuclear-matrix-element calculations, as these can be simultaneously performed for both decay paths with no further assumptions. The theoretical single ß-decay rate has been re-evaluated using a shell-model approach, which indicates a ^{96}Zr single ß-decay lifetime within reach of an experimental verification. The uniqueness of the decay also makes such an experiment interesting for an investigation into the origin of the quenching of the axial-vector coupling constant g_{A}.

12.
Int J Cardiol ; 175(1): 83-9, 2014 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-24857326

RESUMEN

AIMS: Guidelines have been published for improving management of chronic heart failure (CHF). We examined the association between improved guideline adherence and risk for all-cause death in patients with stable systolic HF. METHODS: Data on ambulatory patients (2006-2010) with CHF and reduced ejection fraction (HF-REF) from the Austrian Heart Failure Registry (HIR Austria) were analysed. One-year clinical data and long-term follow-up data until all-cause death or data censoring were available for 1014 patients (age 65 [55-73], male 75%, NYHA class I 14%, NYHA II 56%, NYHA III/IV 30%). A guideline adherence indicator (GAI [0-100%]) was calculated for each patient at baseline and after 12 ± 3 months that considered indications and contraindications for ACE-I/ARB, beta blockers, and MRA. Patients were considered ΔGAI-positive if GAI improved to or remained at high levels (≥ 80%). ΔGAI50+ positivity was ascribed to patients achieving a dose of ≥ 50% of suggested target dose. RESULTS: Improvements in GAI and GAI50+ were associated with significant improvements in NYHA class and NT-proBNP (1728 [740-3636] to 970 [405-2348]) (p<0.001). Improvements in GAI50+, but not GAI, were independently predictive of lower mortality risk (HR 0.55 [95% CI 0.34-0.87; p=0.01]) after adjustment for a large variety of baseline parameters and hospitalisation for heart failure during follow-up. CONCLUSIONS: Improvement in guideline adherence with particular emphasis on dose escalation is associated with a decrease in long-term mortality in ambulatory HF-REF subjects surviving one year after registration.


Asunto(s)
Fármacos Cardiovasculares/administración & dosificación , Adhesión a Directriz/tendencias , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/mortalidad , Cumplimiento de la Medicación , Anciano , Australia/epidemiología , Enfermedad Crónica , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Mortalidad/tendencias , Sistema de Registros
13.
Neuroscience ; 268: 118-27, 2014 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-24657459

RESUMEN

Cerebral activations during olfactory mental imagery are fairly well investigated in healthy participants but little attention has been given to olfactory imagery in patients with olfactory loss. To explore whether olfactory loss leads to deficits in olfactory imagery, neural responses using functional magnetic resonance imaging (fMRI) and self-report measures were investigated in 16 participants with acquired olfactory loss and 19 control participants. Participants imagined both pleasant and unpleasant odors and their visual representations. Patients reported less vivid olfactory but not visual images than controls. Results from neuroimaging revealed that activation patterns differed between patients and controls. While the control group showed stronger activation in olfactory brain regions for unpleasant compared to pleasant odors, the patient group did not. Also, activation in critical areas for olfactory imagery was correlated with the duration of olfactory dysfunction, indicating that the longer the duration of dysfunction, the more the attentional resources were employed. This indicates that participants with olfactory loss have difficulties to perform olfactory imagery in the conventional way. Regular exposure to olfactory information may be necessary to maintain an olfactory imagery capacity.


Asunto(s)
Encéfalo/fisiopatología , Imaginación/fisiología , Trastornos del Olfato/fisiopatología , Trastornos del Olfato/psicología , Percepción Olfatoria/fisiología , Adulto , Anciano , Nivel de Alerta/fisiología , Atención/fisiología , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Autoinforme , Encuestas y Cuestionarios , Factores de Tiempo , Percepción Visual/fisiología , Adulto Joven
14.
Neuroimage ; 55(3): 1200-7, 2011 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-21236348

RESUMEN

Visual emotional stimuli evoke enhanced activation in early visual cortex areas which may help organisms to quickly detect biologically salient cues and initiate appropriate approach or avoidance behavior. Functional neuroimaging evidence for the modulation of other sensory modalities by emotion is scarce. Therefore, the aim of the present study was to test whether sensory facilitation by emotional cues can also be found in the auditory domain. We recorded auditory brain activation with functional near-infrared-spectroscopy (fNIRS), a non-invasive and silent neuroimaging technique, while participants were listening to standardized pleasant, unpleasant, and neutral sounds selected from the International Affective Digitized Sound System (IADS). Pleasant and unpleasant sounds led to increased auditory cortex activation as compared to neutral sounds. This is the first study to suggest that the enhanced activation of sensory areas in response to complex emotional stimuli is apparently not restricted to the visual domain but is also evident in the auditory domain.


Asunto(s)
Corteza Auditiva/fisiología , Emociones/fisiología , Estimulación Acústica , Adulto , Corteza Auditiva/irrigación sanguínea , Mapeo Encefálico , Circulación Cerebrovascular/fisiología , Interpretación Estadística de Datos , Femenino , Lateralidad Funcional/fisiología , Hemoglobinas/metabolismo , Humanos , Modelos Lineales , Masculino , Oxígeno/sangre , Espectroscopía Infrarroja Corta , Adulto Joven
16.
Artículo en Inglés | MEDLINE | ID: mdl-21096471

RESUMEN

Clinical scales represent the golden standard in characterizing awareness for patients in vegetative or in a minimally conscious state. Clinical scales suffer from problems of sensitivity, specificity, subjectivity, and inter-rater reliability. This leads to a misdiagnosis rate of up to 40% and consequences associated with inappropriate treatment decisions. In this study, objective measures including physiological and neurological signals are used to quantify the patient status. Using linear backward regression analysis, 13 variables (based on frequency analysis of the electrocardiogram, heart rate variability, amplitude and latency of the P300, skin conductance responses, changes in the blood pressure and respiration signal) were found to be sufficient to describe 74.7% of the variability of the scores. In this regression model, the P300, electrocardiogram and the blood pressure signal account for most of the variability. More patient data and additional measures will enable refinement of the methods. This new objective-measurement based model of the state of awareness will complement the clinical scales in order to increase the quality of diagnosis.


Asunto(s)
Concienciación/fisiología , Estado Vegetativo Persistente/fisiopatología , Adulto , Femenino , Escala de Coma de Glasgow , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
17.
J Hazard Mater ; 181(1-3): 845-50, 2010 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-20542377

RESUMEN

Contamination of shooting range soils with toxic trace elements, in particular Pb and Sb, is of increasing environmental concern worldwide. We studied the extractability of Sb, and other metals in two shooting range soils: a calcareous soil (pH 8) with low organic carbon (0.5%) and a non-calcareous soil (pH 6.3) with elevated organic carbon content (5%). Both soils contained total concentrations of around 500 mg kg(-1) Pb, 65 mg kg(-1) Cu, 100 mg kg(-1) Zn and 20 mg kg(-1) Sb. We tested the effects of Ca(OH)(2), phosphate and sodium humate amendments on metals and Sb extractability. Extracts with H(2)O and NaNO(3) contained 0.02-0.05% of the total Zn and Pb; 0.1-0.5% of total Ni and Cu and approximately 1% of total Sb. Sequential extraction procedure of Zeien and Brümmer resulted in similar percentages for the sum of the two most labile fractions (F1+F2) in two soils: 10% Pb, and 15-20% Sb. Water and NaNO(3)-extractable Sb concentrations increased after phosphate addition, but were not affected by the addition of sodium humate. The results show that leaching of Sb from shooting ranges into ground and surface waters may generate a serious environmental risk under widely different soils conditions.


Asunto(s)
Armas de Fuego , Metales Pesados/aislamiento & purificación , Contaminantes del Suelo/aislamiento & purificación , Antimonio , Fraccionamiento Químico , Cobre , Plomo , Níquel
18.
Exp Brain Res ; 203(1): 181-91, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20364340

RESUMEN

Human gait is a complex process in the central nervous system that results from the integrity of various mechanisms, including different cortical and subcortical structures. In the present study, we investigated cortical activity during lower limb movement using EEG. Assisted by a dynamic tilt table, all subjects performed standardized stepping movements in an upright position. Source localization of the movement-related potential in relation to spontaneous EEG showed activity in brain regions classically associated with human gait such as the primary motor cortex, the premotor cortex, the supplementary motor cortex, the cingulate cortex, the primary somatosensory cortex and the somatosensory association cortex. Further, we observed a task-related power decrease in the alpha and beta frequency band at electrodes overlying the leg motor area. A temporal activation and deactivation of the involved brain regions as well as the chronological sequence of the movement-related potential could be mapped to specific phases of the gait-like leg movement. We showed that most cortical capacity is needed for changing the direction between the flexion and extension phase. An enhanced understanding of the human gait will provide a basis to improve applications in the field of neurorehabilitation and brain-computer interfaces.


Asunto(s)
Encéfalo/fisiología , Pierna/fisiología , Movimiento/fisiología , Caminata/fisiología , Adulto , Ritmo alfa , Ritmo beta , Mapeo Encefálico , Electroencefalografía , Electromiografía , Femenino , Humanos , Masculino , Músculo Esquelético/fisiología , Dispositivos de Autoayuda , Factores de Tiempo
20.
Cytotherapy ; 9(5): 488-98, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17786610

RESUMEN

BACKGROUND: Tumor cell lines have enormous value for the study of different aspects of cancer biology and have also recently gained great importance in autologous cell-based anti-tumor therapies. However, the use of these cells is still limited because in vitro growth is hampered by suboptimal culture conditions and current media contain fetal bovine serum (FBS), which poses serious safety concerns regarding clinical application. METHODS: To address this drawback, we aimed to develop a strategy for optimization of the culture medium for human medullary thyroid carcinoma (MTC) cell lines as a model system. We combined the general cell screening system (GCSS), which continuously measured the growth behavior of cells in a 96-well plate format, with statistically based experimental designs. RESULTS: The results obtained clearly demonstrated that, just by changing the composition of the basal medium, a significantly enhanced growth rate could be observed, and by subsequent addition of several substances a serum-free cell culture medium could be developed. This medium allowed the propagation of two MTC cell lines comparable with conventionally used serum-supplemented medium. DISCUSSION: We present a fast and easy way to screen for substances that are essential for tumor cell growth in vitro. Furthermore, these tumor cells can be adapted to culture conditions that allow the use of the cells in safe cell-based therapies. This is of utmost importance because of increasing regulatory requirements.


Asunto(s)
Carcinoma/metabolismo , Proliferación Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos/métodos , Neoplasias de la Tiroides/metabolismo , Técnicas de Cultivo de Célula/métodos , Línea Celular Tumoral , Medio de Cultivo Libre de Suero/química , Medio de Cultivo Libre de Suero/farmacología , Medio de Cultivo Libre de Suero/normas , Humanos
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