306 research outputs found
Randomized comparison of total laparoscopic, laparoscopically assisted vaginal and vaginal hysterectomies for myomatous uteri
To compare the operative data and early postoperative outcomes of total laparoscopic hysterectomy (TLH), laparoscopically assisted vaginal hysterectomy (LAVH) and vaginal hysterectomy (VH).
One hundred and eight women requiring hysterectomy for enlarged myomatous uterus were randomly allocated into three treatment arms: TLH (n = 36); LAVH (n = 36); VH (n = 36). Randomization procedure was based on a computer-generated list. The primary outcome was the discharge time comparison. The secondary outcomes were operating time, blood loss, paralytic ileus time, intraoperative complications, postoperative pain, and early postoperative complications.
The mean discharge time was shorter after VH than after LAVH and TLH (P = 0.001). Operating time significantly influenced the discharge time, considered as a dependent variable in general linear model analysis (P = 0.006). In contrast, blood loss did not influence the discharge time (P = 0.55).The mean operating time was significantly shorter in VH than in TLH and LAVH groups (P = 0.000).The intraoperative blood loss was greater during LAVH than during TLH and VH (P = 0.000).Paralytic ileus time was shorter after VH than after TLH and LAVH (P = 0.000). No intraoperative complications or conversion to laparotomy occurred.
VH was the faster operative technique with smaller blood loss and shorter discharge time compared with the others two techniques. So, VH should be considered the preferred approach in patients with enlarged myomatous uteri. When VH is not feasible or salpingo-oophorectomy is required, LAVH or TLH should be considered as valid alternatives. It is necessary to continue prospective comparative studies between the various surgical options to identify the best approach for hysterectomy in each single woman
GIADA performance during Rosetta mission scientific operations at comet 67P
The Grain Impact Analyser and Dust Accumulator (GIADA) instrument onboard Rosetta studied the dust environment of comet 67P/Churyumov–Gerasimenko from 3.7 au inbound, through perihelion, to 3.8 au outbound, measuring the dust flow and the dynamic properties of individual particles. GIADA is composed of three subsystems: 1) Grain Detection System (GDS); 2) Impact Sensor (IS); and 3) Micro-Balances System (MBS). Monitoring the subsystems’ performance during operations is an important element for the correct calibration of scientific measurements. In this paper, we analyse the GIADA inflight calibration data obtained by internal calibration devices for the three subsystems during the period from 1 August 2014 to 31 October 2015. The calibration data testify a nominal behaviour of the instrument during these fifteen months of mission; the only exception is a minor loss of sensitivity for one of the two GDS receivers, attributed to dust contamination
Isolation of Diterpenoids from Jatropha podagrica against Hepatitis C virus
One new lathyrane diterpenoid, Jatropodagrene (1) along with three known compounds have been isolated from the root bark of Jatropha podagrica. The structure of the new compound was established from its 1D and 2D NMR spectra and in comparison with data reported in previous literatures. Compound 1 was highly cytotoxic (98.86% inhibition) to the HCV virus, while compounds 2 (EC50, EC90, CC50 5.8, 33.1, 22.6 μg/mL, respectively) and 3 displayed significant anti HCV activity. This is the first report of the anti hepatitis C virus activity of lathyrane skeleton and J. podagrica.Keywords: Jatropha podagrica; medicinal plant; hepatitis C virus; extract; pure compound
GIADA: its status after the Rosetta cruise phase and on-ground activity in support of the encounter with comet 67P/Churyumov-Gerasimenko
GIADA (Grain Impact Analyser and Dust Accumulator) on-board the Rosetta mission to comet 67P/Churyumov-Gerasimenko was designed to study the physical and dynamical properties of dust particles ejected by the comet during the encounter. In this paper we report the results of the analysis of data collected by GIADA during the past seven years of the cruise phase. During this period the GIADA detection subsystems were switched on for periodic in-flight payload checkouts to monitor their state of-health including potential changes in its performance that could affect its data collection. Only slight variations in sensitivity and dynamical range were identified that will not affect the GIADA measurement capability during the Rosetta comet encounter and rendezvous phase. The GIADA microbalance system detected the presence of low-volatility material over a period of about 169 days when the GIADA cover remained partially opened. It is highly probable that this material originated from the spacecraft itself, as a spacecraft’s outgassing was observed by the ROSINA mass spectrometer (on-board Rosetta) during the cruise phase.
The identification of the low-volatility mass deposited on the microbalances as self-contamination will allow us to evaluate the mass rate background to be subtracted from the GIADA science data. These results obtained from GIADA cruise data analysis coupled with laboratory calibration data obtained from measurements using the GIADA spare model for selected cometary dust analogs will be the basis for the interpretation of the GIADA scientific data
Density and Charge of Pristine Fluffy Particles from Comet 67P/Churyumov–Gerasimenko
The Grain Impact Analyzer and Dust Accumulator (GIADA) instrument on board ESA’s Rosetta mission is constraining the origin of the dust particles detected within the coma of comet 67 P/Churyumov–Gerasimenko (67P). The collected particles belong to two families: (i) compact particles (ranging in size from 0.03 to 1 mm), witnessing the presence of materials that underwent processing within the solar nebula and (ii) fluffy aggregates (ranging in size from 0.2 to 2.5 mm) of sub-micron grains that may be a record of a primitive component, probably linked to interstellar dust. The dynamics of the fluffy aggregates constrain their equivalent bulk density to -3. These aggregates are charged, fragmented, and decelerated by the spacecraft negative potential and enter GIADA in showers of fragments at speeds -1. The density of such optically thick aggregates is consistent with the low bulk density of the nucleus. The mass contribution of the fluffy aggregates to the refractory component of the nucleus is negligible and their coma brightness contribution is less than 15%
67P/C-G inner coma dust properties from 2.2 au inbound to 2.0 auoutbound to the Sun
GIADA (Grain Impact Analyzer and Dust Accumulator) on-board the Rosetta space probe is designed to measure the momentum, mass and speed of individual dust particles escaping the nucleus of comet 67P/Churyumov-Gerasimenko (hereafter 67P). From 2014 August to 2016 June, Rosetta escorted comet 67P during its journey around the Sun. Here, we focus on GIADA data taken between 2015 January and 2016 February which included 67P's perihelion passage. To better understand cometary activity and more specifically the presence of dust structures in cometary comae, we mapped the spatial distribution of dust density in 67P's coma. In this manner, we could track the evolution of high-density regions of coma dust and their connections with nucleus illumination conditions, namely tracking 67P's seasons. We also studied the link between dust particle speeds and their masses with respect to heliocentric distance, i.e. the level of cometary activity. This allowed us to derive a global and a local correlation of the dust particles' speed distribution with respect to the H2O production rate. © 2016 The Authors.Peer Reviewe
The Vigilance Decrement in Executive Function Is Attenuated When Individual Chronotypes Perform at Their Optimal Time of Day
Time of day modulates our cognitive functions, especially those related to executive control, such as the ability to inhibit inappropriate responses. However, the impact of individual differences in time of day preferences (i.e. morning vs. evening chronotype) had not been considered by most studies. It was also unclear whether the vigilance decrement (impaired performance with time on task) depends on both time of day and chronotype. In this study, morning-type and evening-type participants performed a task measuring vigilance and response inhibition (the Sustained Attention to Response Task, SART) in morning and evening sessions. The results showed that the vigilance decrement in inhibitory performance was accentuated at non-optimal as compared to optimal times of day. In the morning-type group, inhibition performance decreased linearly with time on task only in the evening session, whereas in the morning session it remained more accurate and stable over time. In contrast, inhibition performance in the evening-type group showed a linear vigilance decrement in the morning session, whereas in the evening session the vigilance decrement was attenuated, following a quadratic trend. Our findings imply that the negative effects of time on task in executive control can be prevented by scheduling cognitive tasks at the optimal time of day according to specific circadian profiles of individuals. Therefore, time of day and chronotype influences should be considered in research and clinical studies as well as real-word situations demanding executive control for response inhibition.This work was supported by the Spanish Ministerio de Ciencia e Innovación (Ramón y Cajal programme: RYC-2007-00296 and PLAN NACIONAL de I+D+i: PSI2010-15399) and Junta de Andalucía (SEJ-3054)
GIADA: shining a light on the monitoring of the comet dust production from the nucleus of 67P/Churyumov Gerasimenko
Context. During the period between 15 September 2014 and 4 February 2015, the Rosetta spacecraft accomplished the circular orbit phase around the nucleus of comet 67P/Churyumov-Gerasimenko (67P). The Grain Impact Analyzer and Dust Accumulator (GIADA) onboard Rosetta monitored the 67P coma dust environment for the entire period.
Aims. We aim to describe the dust spatial distribution in the coma of comet 67P by means of in situ measurements. We determine dynamical and physical properties of cometary dust particles to support the study of the production process and dust environment modification.
Methods. We analyzed GIADA data with respect to the observation geometry and heliocentric distance to describe the coma dust spatial distribution of 67P, to monitor its activity, and to retrieve information on active areas present on its nucleus. We combined GIADA detection information with calibration activity to distinguish different types of particles that populate the coma of 67P: compact particles and fluffy porous aggregates. By means of particle dynamical parameters measured by GIADA, we studied the dust acceleration region.
Results. GIADA was able to distinguish different types of particles populating the coma of 67P: compact particles and fluffy porous aggregates. Most of the compact particle detections occurred at latitudes and longitudes where the spacecraft was in view of the comet’s neck region of the nucleus, the so-called Hapi region. This resulted in an oscillation of the compact particle abundance with respect to the spacecraft position and a global increase as the comet moved from 3.36 to 2.43 AU heliocentric distance. The speed of these particles, having masses from 10-10 to 10-7 kg, ranged from 0.3 to 12.2 m s−1. The variation of particle mass and speed distribution with respect to the distance from the nucleus gave indications of the dust acceleration region. The influence of solar radiation pressure on micron and submicron particles was studied. The integrated dust mass flux collected from the Sun direction, that is, particles reflected by solar radiation pressure, was three times higher than the flux coming directly
from the comet nucleus. The awakening 67P comet shows a strong dust flux anisotropy, confirming what was suggested by on-ground dust coma observations performed in 2008
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