Nuisance effects in inter-scan functional connectivity estimates before and after nuisance regression

Publication date: Available online 20 July 2019Source: NeuroImageAuthor(s): Alican Nalci, Wenjing Luo, Thomas T. LiuAbstractIn resting-state functional MRI, the correlation between blood-oxygenation-level-dependent (BOLD) signals across brain regions is used to estimate the functional connectivity (FC) of the brain. FC estimates are prone to the influence of nuisance factors including scanner-related artifacts and physiological modulations of the BOLD signal. Nuisance regression is widely performed to reduce the effect of nuisance factors on FC estimates on a per-scan basis. However, a dedicated analysis of nuisance effects on the variability of FC metrics across a collection of scans has been lacking. This work investigates the effects of nuisance factors on the variability of FC estimates across a collection of scans both before and after nuisance regression. Inter-scan variations in FC estimates are shown to be significantly correlated with the geometric norms of various nuisance terms, including head motion measurements, signals derived from white-matter and cerebrospinal regions, and the whole-brain global signal (GS) both before and after nuisance regression. In addition, it is shown that GS regression (GSR) can introduce GS norm-related fluctuations that are negatively correlated with inter-scan FC estimates. The empirical results are shown to be largely consistent with the predictions of a theoretical framework previously developed for the characterization of dynamic ...
Source: NeuroImage - Category: Neuroscience Source Type: research

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The objective of the study was to (1) characterize and compare the chemical composition at the surface, subsurface and in the bulk of thin plastic films used for portosystemic shunt attenuation in their native state and after plasma exposure. (2) Assess the presence, concentration and location of irritant compounds (e.g dicetyl phosphate) within the films.Attenuated Total Reflectance Infrared Spectroscopy (ATR-IR), X-ray Photoelectron Spectroscopy (XPS) and dynamic Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) were used to analyze thirteen thin plastic films. Sample thickness was visualized and measured using S...
Source: Research in Veterinary Science - Category: Veterinary Research Source Type: research
Publication date: December 2019Source: Results in Physics, Volume 15Author(s): Abhilash Pathania, Preeti Thakur, Alex V. Trukhanov, Sergei V. Trukhanov, Larissa V. Panina, Ulrike Lüders, Atul ThakurAbstractThis paper reports on the study of series of tungsten doped Ni0.5Zn0.5WxFe2−xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) ferrites synthesized by a co-precipitation scheme. The crystallite size varies from 62 to 49 nm and the scanning electron microscope (SEM) images show the spinel cubic structure of the powder sample. Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF) confirms the presence of Ni, Zn, W...
Source: Results in Physics - Category: Physics Source Type: research
Publication date: Available online 21 August 2019Source: Journal of Molecular LiquidsAuthor(s): Jitendra Kumar Sahoo, Monidipa Konar, Juhi Rath, Devendra Kumar, Harekrushna SahooAbstractThe current investigation reports the removal of Eriochrome Black T (EBT) from aqueous solution by using magnetic hydroxyapatite (M-HAP), a cost-effective adsorbent compared to the other commercial adsorbents. The M-HAP nanocomposite was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM), Environmental scanning electron (E-SEM), BET surface area analyser, vibrati...
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research
Publication date: Available online 20 August 2019Source: Journal of Molecular LiquidsAuthor(s): Risa Kawai, Shiho Yada, Tomokazu YoshimuraAbstractQuaternary-ammonium-salt-type amphiphilic compounds ([CnAdA][X], where n represents the alkyl chain length (n = 1, 2, 4, 6, 8, or 10), X represents a counterion such as [BF4]−, [PF6]−, trifluoromethanesulfonate ([OTf]−), bis(fluorosulfonyl)amide ([FSA]−), or bis(trifluoromethanesulfonyl)amide ([NTf2]−), and Ad and A of AdA represent the adamantane structure and quaternary ammonium group, respectively) were synthesized. The melting points of the p...
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research
Publication date: Available online 21 August 2019Source: Carbohydrate PolymersAuthor(s): Alma Bockuviene, Jolanta SereikaiteAbstractβ-carotene and chitooligosaccharides are bioactive compounds that find their application in the food industry as well in biomedical fields. However, the application of β-carotene is limited due to its very low water solubility, as well as its air, light and temperature sensitivity. The preparation of β-carotene-chitooligosaccharides complexes by mechanochemical methods was presented. Their physical and chemical properties including solubility, size, zeta potential and radical sc...
Source: Carbohydrate Polymers - Category: Biomedical Science Source Type: research
Publication date: Available online 12 August 2019Source: Carbohydrate PolymersAuthor(s): Abdus Sobhan, Kasiviswanathan Muthukumarappan, Zhisheng Cen, Lin WeiAbstractThe goal of this research is to develop a functional nanocellulose and activated carbon (NAC) film and characterize its biosensing properties for smart packaging applications. The NAC film was prepared from activated carbon powder and nanocellulose gel using the casting method. The nanocellulose contents in the films were varied from 15% to 50% (w/w). Physicochemical properties of the produced films such as electrical conductivity, water absorption capacity, so...
Source: Carbohydrate Polymers - Category: Biomedical Science Source Type: research
Publication date: 1 December 2019Source: Carbohydrate Polymers, Volume 225Author(s): Veronica Nessi, Xavier Falourd, Jean-Eudes Maigret, Karine Cahier, Angelina D’Orlando, Nicolas Descamps, Valérie Gaucher, Chloé Chevigny, Denis LourdinAbstractDifferent amounts of cellulose nanocrystals (CNCs) were added to glycerol-plasticized thermoplastic starch (TPS) to obtain bio-based nanocomposites. First, nanocomposites are prepared by extrusion and their structure is studied at different scales using WAXS (Wide Angle X-ray Scattering) and solid-state NMR (Nuclear Magnetic Resonance) for local/crystalline organi...
Source: Carbohydrate Polymers - Category: Biomedical Science Source Type: research
In conclusion, PACAP27 induced headache and dilated extracerebral arteries (>5 h) and slightly constricted MCA in healthy volunteers. Post hoc analysis of PACAP38 data compared with PACAP27 showed that PACAP isoforms dilates MMA with significantly different magnitude.
Source: Peptides - Category: Biochemistry Source Type: research
Publication date: 1 November 2019Source: Colloids and Surfaces B: Biointerfaces, Volume 183Author(s): Jian-Tao Lin, Hua Chen, Dan Wang, Liang Xiong, Jia-Zhu Li, Gui-hong Chen, Guang-Bin ChenAbstractThe nucleus is one of the most important cellular organelles. Chitosan-grafted poly-(N-3-carbobenzyloxy-lysine) (CCL) decorated with human immunodeficiency virus-1 transactivator of transcription (TAT) can co-deliver p53 and doxorubicin into the nucleus simultaneously, such that their antitumor functions are exerted. However, TAT-CCL has been shown to have an anti-tumor effect only in vitro; the effect in vivo was unsatisfactory...
Source: Colloids and Surfaces B: Biointerfaces - Category: Biochemistry Source Type: research
Publication date: October 2019Source: Thermochimica Acta, Volume 680Author(s): A.C.S. Carvalho, G.A.C. Zangaro, R.P. Fernandes, B. Ekawa, A.L.C.S. Nascimento, B.F. Silva, G.P. Ashton, G.M.B. Parkes, M. Ionashiro, F.J. CairesAbstractIn the present work, the thermal behavior of Lornoxicam drug was studied under oxidizing (air) and pyrolysis (N2) atmospheres using simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), differential scanning calorimetry (DSC), Hot Stage Microscopy (HSM) and Evolved Gas Analysis (EGA) in the form of thermogravimetry coupled to infrared spectroscopy (TG-FTIR) and mass spect...
Source: Thermochimica Acta - Category: Chemistry Source Type: research
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