366 research outputs found
SEXTANT X-Ray Pulsar Navigation Demonstration: Additional On-Orbit Results
The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission, a NASA Astrophysics Explorer Mission of Opportunity to the International Space Station, launched in June of 2017. In late 2017, SEXTANT successfully completed a first demonstration of in-space and autonomous X-ray pulsar navigation (XNAV). This form of navigation relies on processing faint signals from millisecond pulsars-rapidly rotating neutron stars that appear to pulsate in the X-ray band-and could potentially provide a GPS-like navigation capability applicable throughout the solar-system and beyond. In this work, we briefly review prior SEXTANT results and then present new results focusing on: making use of the high- flux but rotationally unstable Crab pulsar, and using XNAV to estimate position, velocity, and time in the presence of an imperfect local clock
Incidencia y mortalidad del cáncer de próstata en Navarra (España)
Fundamento. A nivel mundial, el cáncer de próstata es uno de los tumores malignos más comúnmente diagnosticados en los hombres. En este estudio, se analizan las tendencias
de la incidencia y mortalidad de cáncer de próstata, global
y por grupos de edad, para mostrar la situación epidemiológica
pasada y actual de la enfermedad en Navarra (España).
Método. Para el estudio se utilizaron los casos incidentes
diagnosticados entre 1975 y 2010, y las muertes observadas
entre 1975 y 2013. Los datos fueron proporcionados por el
Registro de Cáncer de Navarra y el Instituto Nacional de Estadística
respectivamente. Se calcularon las tasas de incidencia
y mortalidad estandarizadas por edad, los puntos de cambio
y el porcentaje de cambio anual (PCA) mediante modelos de
regresión de joinpoint. Se usaron modelos unidimensionales
de P-splines para estimar proyecciones hasta 2016.
Resultados. Se observó un considerable incremento en las
tasas de incidencia de cáncer de próstata en hombres de
45-74 años, con PCA de +4,5% (p<0,001), +9,5% (p<0,001) y
+2,4% (p<0,05) en los periodos 1975-1990, 1990-2000 y 2000-
2010, respectivamente. En el grupo de mayores de 74 se
registró un aumento de incidencia en el período 1975-1999
(PCA +3,3%, p<0,001), seguido de una disminución significativa
hasta 2010 (PCA -4,0%, p<0,01). Las tasas de mortalidad
aumentaron hasta 1995 (PCA +2,2%, p<0,001), mientras que
descendieron en el periodo 1995-2013 (PCA -3.4%, p<0,001).
Conclusión. Aunque las tasas globales de incidencia de
cáncer de próstata parecen estabilizarse en 2002-2010 en
Navarra, las tendencias fueron diferentes según los grupos
de edad, aumentando en los hombres de 45-74 años y disminuyendo
en el grupo de mayores de 74 años. Se observó una
disminución en las tasas de mortalidad en ambos grupos de
edad desde 1995. Cambios en el uso del antígeno prostático
específico para cribado en los próximos años podrían afectar
las futuras tendencias del cáncer de próstata.
Palabras clave. Cáncer de Próstata. Incidencia. Mortalidad.
Estimaciones. TendenciasBackground. Prostate cancer is one of the most commonly
diagnosed malignancies among males worldwide. In this
study, overall and age-specific incidence and mortality
trends are analyzed in order to present the past and current
epidemiological situation of the disease in Navarre (Spain).
Methods. Population-based incidence data from the 1975-
2010 period, provided by the Cancer Registry of Navarre
and prostate cancer specific mortality data for 1975-2013,
provided by the Spanish Statistical Office, were used in the
analysis. Age-standardized incidence and mortality rates,
change-points and annual percentage changes (APC) were
estimated by joinpoint regression analysis. One-dimensional
P-spline models were used to estimate projections up to
2016.
Results. Considerable increases of cancer incidence rates
in men aged 45-74 years were observed, with APC of +4.5%
(p<0.001), +9.5% (p<0.001) and +2.4% (p<0.05) in the 1975-
1990, 1990-2000 and 2000-2010 periods, respectively. In the
older than 74 age-group, an increase of incidence rates in
the 1975-1999 period was registered (APC +3.3%, p<0.001),
followed by a significant decrease up to 2010 (APC -4.0%,
p<0.01). Mortality rates rose until 1995 (APC +2.2%, p<0.001)
whereas a decline occurred afterwards up to 2013 (APC
-3.4%, p<0.001).
Conclusion. Even though overall prostate cancer incidence
rates seem to have stabilized in 2002-2010 in Navarra, trends
were different by age groups: increased in men 45-74 years
old and decreased in the 75+ year age-group. A decline in
mortality rates was observed in both age groups since about
1995. Changes in the use of prostate specific antigen test for
screening in oncoming years could affect future prostate
cancer trends
Comparative performance of four rapid Ebola antigen-detection lateral flow immunoassays during the 2014-2016 Ebola epidemic in West Africa
BACKGROUND: Without an effective vaccine, as was the case early in the 2014-2016 Ebola Outbreak in West Africa, disease control depends entirely on interrupting transmission through early disease detection and prompt patient isolation. Lateral Flow Immunoassays (LFI) are a potential supplement to centralized reference laboratory testing for the early diagnosis of Ebola Virus Disease (EVD). The goal of this study was to assess the performance of commercially available simple and rapid antigen detection LFIs, submitted for review to the WHO via the Emergency Use Assessment and Listing procedure. The study was performed in an Ebola Treatment Centre laboratory involved in EVD testing in Sierra Leone. In light of the current Ebola outbreak in May 2018 in the Democratic Republic of Congo, which highlights the lack of clarity in the global health community about appropriate Ebola diagnostics, our findings are increasingly critical. METHODS: A cross-sectional study was conducted to assess comparative performance of four LFIs for detecting EVD. LFIs were assessed against the same 328 plasma samples and 100 whole EDTA blood samples, using the altona RealStar Filovirus Screen real-time RT-PCR as the bench mark assay. The performance of the Public Health England (PHE) in-house Zaire ebolavirus-specific real time RT-PCR Trombley assay was concurrently assessed. Statistical analysis using generalized estimating equations was conducted to compare LFI performance. FINDINGS: Sensitivity and specificity varied between the LFIs, with specificity found to be significantly higher for whole EDTA blood samples compared to plasma samples in at least 2 LFIs (P≤0.003). Using the altona RT-PCR assay as the bench mark, sensitivities on plasma samples ranged from 79.53% (101/127, 95% CI: 71.46-86.17%) for the DEDIATEST EBOLA (SD Biosensor) to 98.43% (125/127, 95% CI: 94.43-99.81%) for the One step Ebola test (Intec). Specificities ranged from 80.20% (158/197, 95% CI: 74.07-88.60%) for plasma samples using the ReEBOV Antigen test Kit (Corgenix) to 100.00% (98/98, 95% CI: 96.31-100.00%) for whole blood samples using the DEDIATEST EBOLA (SD Biosensor) and SD Ebola Zaire Ag (SD Biosensor). Results also showed the Trombley RT-PCR assay had a lower limit of detection than the altona assay, with some LFIs having higher sensitivity than the altona assay when the Trombley assay was the bench mark. INTERPRETATION: All of the tested EVD LFIs may be considered suitable for use in an outbreak situation (i.e. rule out testing in communities), although they had variable performance characteristics, with none possessing both high sensitivity and specificity. The non-commercial Trombley Zaire ebolavirus RT-PCR assay warrants further investigation, as it appeared more sensitive than the current gold standard, the altona Filovirus Screen RT-PCR assay
The influence of dexamethasone on postoperative swelling and neurosensory disturbances after orthognathic surgery: a randomized controlled clinical trial
Background: Orthognathic surgery is associated with considerable swelling and neurosensory disturbances. Serious swelling can lead to great physical and psychological strain. A randomized, prospective, controlled clinical trial was realized in order to evaluate the effect of a preoperative intravenous dexamethasone injection of 40 mg on postoperative swelling and neurosensory disturbances after orthognathic surgery. Methods: Thirty-eight patients (27 male and 11 female) patients, all with the indication for an orthognathic surgery, were enrolled in this study (mean age: 27.63 years, range: 16-61 years) and randomly divided into two groups (study group/control group). Both groups underwent either maxillary and/or mandibular osteotomies, resulting in three subgroups according to surgical technique (A: LeFort I osteotomy, B: bilateral sagittal split osteotomy (BSSO), C: bimaxillary osteotomy). The study group received a single preoperative intravenous injection of 40 mg dexamethasone. Facial edema was measured by 3D surface scans on the 1st, 2nd, 5th, 14th and 90th postoperative day. Furthermore, neurosensory disturbances on the 2nd, 5th, 14th and 90th postoperative day were investigated by thermal stimulation. Results: Facial edema after LeFort I osteotomy, BSSO and bimaxillary osteotomy showed a significant decrease in the study group compared to the control group (P = 0.048, P = 0.045, P < 0.001). The influence of dexamethasone on neurosensory disturbances was not significant for the inferior alveolar nerve (P = 0.746) or the infraorbital nerve (P = 0.465). Conclusions: Patients undergoing orthognathic surgery should receive a preoperative injection of dexamethasone in order to control and reduce edema. However, there was no influence of dexamethasone on reduction of neurosensory disturbances
Persistent symptoms after COVID-19 are not associated with differential SARS-CoV-2 antibody or T cell immunity.
Among the unknowns in decoding the pathogenesis of SARS-CoV-2 persistent symptoms in Long Covid is whether there is a contributory role of abnormal immunity during acute infection. It has been proposed that Long Covid is a consequence of either an excessive or inadequate initial immune response. Here, we analyze SARS-CoV-2 humoral and cellular immunity in 86 healthcare workers with laboratory confirmed mild or asymptomatic SARS-CoV-2 infection during the first wave. Symptom questionnaires allow stratification into those with persistent symptoms and those without for comparison. During the period up to 18-weeks post-infection, we observe no difference in antibody responses to spike RBD or nucleoprotein, virus neutralization, or T cell responses. Also, there is no difference in the profile of antibody waning. Analysis at 1-year, after two vaccine doses, comparing those with persistent symptoms to those without, again shows similar SARS-CoV-2 immunity. Thus, quantitative differences in these measured parameters of SARS-CoV-2 adaptive immunity following mild or asymptomatic acute infection are unlikely to have contributed to Long Covid causality. ClinicalTrials.gov (NCT04318314)
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