6,655 research outputs found
Comparison of the Aptima HIV-1 Quant Dx Assay with the COBAS\uae AmpliPrep/COBAS\uae TaqMan\uae HIV-1 v2.0 Test for HIV-1 Viral Load Quantification in Plasma Samples from HIV-1-Infected Patients.
Background and aims: HIV\u20101 RNA viral load (VL) in plasma samples of HIV\u20101\u2013positive
patients is used to assess the level of viral replication, the risk of disease progression, and the
response and efficacy to antiretroviral treatment. Knowing the performance of different tests
for HIV\u20101 RNA detection is, therefore, important for clinical care. This study compared the performance
of the recently introduced Aptima HIV\u20101 Quant Dx assay (Hologic, Inc) and the standard
COBAS AmpliPrep/COBAS TaqMan HIV\u20101 v2.0 Test (CAP/CTM2) (Roche Molecular System,
Inc) for HIV\u20101 RNA quantitation.
Methods: Assay performance was assessed using 335 clinical samples, a standard HIV\u20101 low
VL panel, and 2 diluted samples from well\u2010characterized patients infected with different HIV\u20101
subtypes tested in 5 replicates over 3 days. All samples were tested on both assays to evaluate
inter\u2010assay agreement, both qualitatively and quantitively. Altogether, we evaluated assay sensitivity,
linearity, accuracy, precision, repeatability, and reproducibility.
Results: Assay agreement for qualitative results in 335 clinical samples was fair (80.6%). Correlation
of quantitative assay results (n = 164) was excellent (R2 = 0.97), with 96.3% of the results
within the 95% limit of assay agreement ( 120.42 to +0.86 log), and 98.8% within 1 log of each
other. Aptima\u2010HIV\u20101 yielded results, on average, 0.22 log higher than CAP/CTM2. Both assays
accurately quantitated the HIV\u20101 standard at low VL (R2 65 0.94), with all samples within 0.5 log
of the target.
Conclusion: Aptima\u2010HIV\u20101 assay demonstrated sensitivity, accuracy, reproducibility, and precision
for the detection and quantitation of HIV\u20101 RNA across a wide dynamic range of VLs. Its
performance, together with full automation and high throughput, suggests that Aptima\u2010HIV\u20101
could be a suitable assay for reliable monitoring of HIV\u20101 VL in patients undergoing treatment
IN VIVO AND IN VITRO EFFECTS OF BIDENS PILOSA L. (ASTERACEAE) LEAF AQUEOUS AND ETHANOL EXTRACTS ON PRIMED-OESTROGENIZED RAT UTERINE MUSCLE.
Bidens pilosa L. is an Asteraceae growing in tropical zones, and traditionally utilized worldwide in herbal medicine. The present work is based on its traditional use during child birth as a labour facilitator. In vivo tests of acute toxicity showed a weak toxic effect for both extracts but the toxicity of the ethanol extract (LD50=6.15g/kg) was upper than that of the aqueous extract (LD50=12.30g/kg). The three-days uterotrophic assay on immature mice showed body weight gain followed by a concentration-dependent decrease up to 4mg/g and a concentration dependent uterine wet weight increase. The ethanol extract exhibited the higher body weight gain representing 22.8±0.7%, (P0.001), at the concentration of 500”g/g/day, while the aqueous extract was significantly more efficient on the uterine wet weight gain of 0.24±0.001% (P0.05), at the concentration of 1000”g/g/day. In vitro isometric contraction measurement of oestrogen-primed rat uterine strips showed a significant high aqueous extract-induced contractile effect from 0.03-1.97mg/ml: on the amplitude of contraction (EC50 = 0.44±0.10mg/ml, P0.05), and on the rate (1.21±0.25mg/ml, P0.05). Inspite of the higher effect of the aqueous extract on the tonus (57.23±23%), the ethanol extract showed a high effect (EC50= 0.34±0.09mg/ml, P0.05). The weak toxicity, the estrogenic-like and the oxytocic-like activities observed could explain the empirical use of Bidens pilosa leaf aqueous extract as an uterotonic preparation to enhance labour, probably due to the presence of biologically active compound(s) which act directly on the uterine muscle
The Evolution of Cognitive Load Theory and the Measurement of Its Intrinsic, Extraneous and Germane Loads: A Review
Cognitive Load Theory has been conceived for supporting instructional design through the use of the construct of cognitive load. This is believed to be built upon three types of load: intrinsic, extraneous and germane. Although Cognitive Load Theory and its assumptions are clear and well-known, its three types of load have been going through a continuous investigation and re-definition. Additionally, it is still not clear whether these are independent and can be added to each other towards an overall measure of load. The purpose of this research is to inform the reader about the theoretical evolution of Cognitive Load Theory as well as the measurement techniques and measures emerged for its cognitive load types. It also synthesises the main critiques of scholars and the scientific value of the theory from a rationalist and structuralist perspective
High Voltage System for the CMS Electromagnetic Calorimeter
The CMS electromagnetic calorimeter (ECAL) is made of about 75000 lead tungstate crystals. The 61200 crystals of the barrel part are read by avalanche photodiodes (APD) with internal amplification of the signal. Since the gain strongly depends on the bias voltage, the APDs require a very stable power supply system. To preserve the high energy resolution of the calorimeter, a stability of the bias voltage of the order of 10^-4 is required over several months, a typical interval between absolute calibrations of the full read-out chain with physics events. This paper describes the High Voltage power supply system developed for CMS ECAL and its performances as measured in laboratory tests and during test-beam operations of several modules of the calorimeter
Gleam: the GLAST Large Area Telescope Simulation Framework
This paper presents the simulation of the GLAST high energy gamma-ray
telescope. The simulation package, written in C++, is based on the Geant4
toolkit, and it is integrated into a general framework used to process events.
A detailed simulation of the electronic signals inside Silicon detectors has
been provided and it is used for the particle tracking, which is handled by a
dedicated software. A unique repository for the geometrical description of the
detector has been realized using the XML language and a C++ library to access
this information has been designed and implemented.Comment: 10 pages, Late
The CMS ECAL Barrel HV system
The CMS electromagnetic calorimeter (ECAL) comprises 75848 scintillating lead tungstate crystals. 61200 crystals are contained in the ECAL Barrel section and are read out by avalanche photodiode (APD) with internal gain of about 50. This gain is achieved with a high voltage (HV) of about 400 Volts. The gain stability requirement implies a supply voltage stable to within 0.01%. We describe our experience with the installed Barrel HV power supply system, which has been used for data taking since 2008
IGEC2: A 17-month search for gravitational wave bursts in 2005-2007
We present here the results of a 515 days long run of the IGEC2 observatory,
consisting of the four resonant mass detectors ALLEGRO, AURIGA, EXPLORER and
NAUTILUS. The reported results are related to the fourfold observation time
from Nov. 6 2005 until Apr. 14 2007, when Allegro ceased its operation. This
period overlapped with the first long term observations performed by the LIGO
interferometric detectors. The IGEC observations aim at the identification of
gravitational wave candidates with high confidence, keeping the false alarm
rate at the level of 1 per century, and high duty cycle, namely 57% with all
four sites and 94% with at least three sites in simultaneous observation. The
network data analysis is based on time coincidence searches over at least three
detectors: the four 3-fold searches and the 4-fold one are combined in a
logical OR. We exchanged data with the usual blind procedure, by applying a
unique confidential time offset to the events in each set of data. The
accidental background was investigated by performing sets of 10^8 coincidence
analyses per each detector configuration on off-source data, obtained by
shifting the time series of each detector. The thresholds of the five searches
were tuned so as to control the overall false alarm rate to 1/century. When the
confidential time shifts was disclosed, no gravitational wave candidate was
found in the on-source data. As an additional output of this search, we make
available to other observatories the list of triple coincidence found below
search thresholds, corresponding to a false alarm rate of 1/month.Comment: 10 pages, 8 figures Accepted for publication on Phys. Rev.
Epidermoid cyst of the floor of the mouth: two case reports
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Results of the IGEC-2 search for gravitational wave bursts during 2005
The network of resonant bar detectors of gravitational waves resumed
coordinated observations within the International Gravitational Event
Collaboration (IGEC-2). Four detectors are taking part in this collaboration:
ALLEGRO, AURIGA, EXPLORER and NAUTILUS. We present here the results of the
search for gravitational wave bursts over 6 months during 2005, when IGEC-2 was
the only gravitational wave observatory in operation. The network data analysis
implemented is based on a time coincidence search among AURIGA, EXPLORER and
NAUTILUS, keeping the data from ALLEGRO for follow-up studies. With respect to
the previous IGEC 1997-2000 observations, the amplitude sensitivity of the
detectors to bursts improved by a factor about 3 and the sensitivity bandwidths
are wider, so that the data analysis was tuned considering a larger class of
detectable waveforms. Thanks to the higher duty cycles of the single detectors,
we decided to focus the analysis on three-fold observation, so to ensure the
identification of any single candidate of gravitational waves (gw) with high
statistical confidence. The achieved false detection rate is as low as 1 per
century. No candidates were found.Comment: 10 pages, to be submitted to Phys. Rev.
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