212 research outputs found
Effect of Sub-energy Windows’ Parameters on the Triple Energy Window Scatter Correction Method Accuracy in 99mTc SPECT Imaging
Scatter correction in SPECT quantification is of major importance to compensation for the scatter contribution under the photopeak. The triple energy windows method (TEW) is one of the suggested ways for scatter correction that are widely used in clinical routine. However, it can be a source of additional noise if the width or the number of sub-energy windows is not accurately chosen. To determine the precise scatter estimation windows settings under the 99mTc photopeak, scatter fraction was calculated for different sub-energy widths and numbers through GATE Monte Carlo simulation, for a main energy window of 15 %, centered at 140 keV. Four different acquisitions, with cold or hot inserts in a warm or a cold background, were studied. The estimation was done by two methods. The first method was the extraction of the number of detected Compton photons under the photopeak, therefore considered as the true scattered photons. The second method was the application of TEW method to the simulated energy spectra. The comparison of results corresponding to both methods shows a good agreement in two cases: simultaneous 7 % and 5 % sub-energy windows, respectively, positioned on the left and the right of the main energy window, and the second case is a 3 % left sub-energy window without a right sub-energy window. These sub-energy windows were then applied to experimental tomographic acquisitions to assess their impact on contrast, relative noise of the background (RNB), signal‑to‑noise ratio (SNR), integral uniformity (IU), and tomographic spatial resolution. Good results for these quantitative parameters were acquired with simultaneous 7 % and 5 % sub-energy windows. However, there was very little enhancement for tomographic spatial resolution
Enhancement of 2,3-butanediol production by Klebsiella pneumoniae PTCC 1290: Application of Taguchi methodology for process optimization
2,3-Butanediol production parameter optimization using Klebsiella pneumoniae PTCC 1290 was performed using the design of experiments available in the form of an orthogonal array and a software for automatic design and analysis of the experiments, both based on Taguchi protocol. Optimal levels of physical parameters and key media components namely temperature, pH, inoculum size, agitation, acetic acid and succinic acid were determined. 2,3-Butanediol production obtained from the 18 sets offermentation experiments performed with the selected factors and levels were further processed with Qualitek-4 software at bigger is better as quality character. The optimized conditions showed an enhanced 2,3-butanediol production of 35.8% (from 11.856 to 18.459 g l-1). The optimal combinations of factors obtained from the proposed design of experiments methodology was further validated by conducting fermentation experiments and the obtained results revealed an enhanced 2,3-butanediol production of 25.8%. Taguchi approach of design of experiments resulted in evaluating the main and interaction effects of the factors individually and in combinatio
Multilevel Analysis on the Factors Associated with Low Birth Weight in Temanggung, Central Java
Background: Infants with low birth weight or LBW is one of the risk factors for infant mortality. Complications LBW actually can be prevented and dealt with, but is constrained by access to health care, socio-economic circumstances, a referral system that has not gone well, delays in early detection and awareness of parents to seek medical help. By looking at the number of deaths caused by LBW remains high, and research on the causes of LBW widely used partial analysis, and have not been analyzed in stages, the researchers conducted this research with multilevel analysis.Subjects and Method: This was an observational studt with case control design. A total sample of 120 infants were selected by fixed disease sampling with a ratio of 1: 2 between cases and controls. Data were analyzed using multiple logistic regression.Results: There are three variables at the individual level were significantly associated with LBW and was statistically significant can among others, mother's education (OR= 0.19; 95% CI= 0:07 to 0.53; p= 0.001), history of ANC t (OR= 7.76; 95% CI= 2.18 to 27.62; p= 0.002) and the nutritional mother status (OR= 5.61; 95% CI= 0.21 to 0.79; p= 0.008) and the variables that are not statistically significant is the mother's age and family income, and there are no contextual role within house with wellness facilities with LBW expressed by ICC < 0.001.Conclusion: The influence of maternal education, a history of the ANC examination and nutritional status of mothers with LBW and there is no contextual role of distance between home and health care facilities with LBW. This study suggests to health professional to improve the coverage of the ANC.Keywords: multilevel analysis, factor low birth weightCorrespondence: Yulia Nur Khayati. School of Health and sciences, STIKes Ngudi Waluyo, Ungaran, Indonesia. Email: [email protected] of Maternal and Child Health (2016), 1(1): 7-12https://doi.org/10.26911/thejmch.2016.01.01.0
All-sky Search for High-Energy Neutrinos from Gravitational Wave Event GW170104 with the ANTARES Neutrino Telescope
Advanced LIGO detected a significant gravitational wave signal (GW170104)
originating from the coalescence of two black holes during the second
observation run on January 4, 2017. An all-sky high-energy
neutrino follow-up search has been made using data from the ANTARES neutrino
telescope, including both upgoing and downgoing events in two separate
analyses. No neutrino candidates were found within s around the GW
event time nor any time clustering of events over an extended time window of
months. The non-detection is used to constrain isotropic-equivalent
high-energy neutrino emission from GW170104 to less than
erg for a spectrum
The ANTARES Collaboration: Contributions to ICRC 2017 Part I: Neutrino astronomy (diffuse fluxes and point sources)
Papers on neutrino astronomy (diffuse fluxes and point sources, prepared for
the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by
the ANTARES Collaboratio
The ANTARES Collaboration: Contributions to ICRC 2017 Part III: Searches for dark matter and exotics, neutrino oscillations and detector calibration
Papers on the searches for dark matter and exotics, neutrino oscillations and
detector calibration, prepared for the 35th International Cosmic Ray Conference
(ICRC 2017, Busan, South Korea) by the ANTARES Collaboratio
The ANTARES Collaboration: Contributions to ICRC 2017 Part II: The multi-messenger program
Papers on the ANTARES multi-messenger program, prepared for the 35th
International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the
ANTARES Collaboratio
New Method to Calculate the Sign and Relative Strength of Magnetic Interactions in Low-Dimensional Systems on the Basis of Structural Data
The connection of strength of magnetic interactions and type ordering the
magnetic moments with crystal chemical characteristics in low-dimensional
magnets is investigated. The new method to calculate the sign and relative
strength of magnetic interactions in low-dimensional systems on the basis of
the structural data is proposed. This method allows to estimate magnetic
interactions not only inside low-dimensional fragments but also between them,
and also to predict the possibility of the occurrence of magnetic phase
transitions and anomalies of the magnetic interactions. Moreover, it can be
used for search of low-dimensional magnets among the compounds whose crystal
structures are known. The possibilities of the method are illustrated in an
example of research of magnetic interactions in familiar low-dimensional
magnets SrCu2(BO3)2, CaCuGe2O6, CaV4O9, Cu2Te2O5Cl2, Cu2Te2O5Br2, BaCu2Si2O7,
BaCu2Ge2O7, BaCuSi2O6, LiCu2O2, and NaCu2O2.Comment: 18 pages, 8 figures, 2 tables, published versio
EMMPRIN Promotes Melanoma Cells Malignant Properties through a HIF-2alpha Mediated Up-Regulation of VEGF-Receptor-2
EMMPRIN's expression in melanoma tissue was reported to be predictive of poor prognosis. Here we demonstrate that EMMPRIN up-regulated VEGF receptor-2 (VEGFR-2) in two different primary melanoma cell lines and consequently increased migration and proliferation of these cells while inhibiting their apoptosis. SiRNA inhibition of VEGFR-2 expression abrogated these EMMPRIN effects. EMMPRIN regulation of VEGFR-2 was mediated through the over-expression of HIF-2α and its translocation to the nucleus where it forms heterodimers with HIF-1β. These results were supported by an in vivo correlation between the expression of EMMPRIN with that of VEGFR-2 in human melanoma tissues as well as with the extent of HIF-2α localization in the nucleus. They demonstrate a novel mechanism by which EMMPRIN promotes tumor progression through HIF-2α/VEGFR-2 mediated mechanism, with an autocrine role in melanoma cell malignancy. The inhibition of EMMPRIN in cancer may thus simultaneously target both the VEGFR-2/VEGF system and the matrix degrading proteases to block tumor cell growth and invasion
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