52 research outputs found
Cross-sectional chest circumference and shape development in infants
Objective: This study investigates the development of the thoracic cross-section at the nipple line level during the early stages of life. Unlike the descriptive awareness regarding chest development course, there exist no quantitative references concerning shape, circumference and possible dependencies to age, gender or body weight. The proposed mathematical relations are expected to help create guidelines for more realistic modelling and potential detection of abnormalities. One potential application is lung electrical impedance tomography (EIT) monitoring where accurate chest models are crucial in both extracting reliable parameters for regional ventilation function and design of EIT belts. Despite their importance, such reference data is not readily available for the younger age range due to insufficient data amid the regulations of neonatal imaging. Results: Chest circumference shows the highest correlation to body weight following the relation fx=18.3735ln0.0012x+2.1010 where x is the body weight in grams and f(x) is the chest circumference in cm at the nipple line level. No statistically significant difference in chest circumference between genders was detected. However, the shape indicated signs of both age and gender dependencies with on average boys developing a more rectangular shape than girls from the age of 1 years and 9 months
Towards a thoracic conductive phantom for EIT
Phantom experiments are a crucial step for testing new hardware or imaging algorithms for electrical impedance tomography (EIT) studies. However, constructing an accurate phantom for EIT research remains critical; some studies have attempted to model the skull and breasts, and even fewer, as yet, have considered the thorax. In this study, a critical comparison between the electrical properties (impedance) of three materials is undertaken: a polyurethane foam, a silicone mixture and a thermoplastic polyurethane filament. The latter was identified as the most promising material and adopted for the development of a flexible neonatal torso. The validation is performed by the EIT image reconstruction of the air filled cavities, which mimic the lung regions. The methodology is reproducible for the creation of any phantom that requires a slight flexibility
Solvent-free synthesis and key intermediate isolation in Ni2Dy2 catalyst development in the domino ring-opening electrocyclization reaction of furfural and amines
A solvent-free methodology that yields trans-4,5-diaminocyclopent-2-enones, main domains of natural products and a variety of N-heterocycles, is described. The bimetallic catalyst [NiII2DyIII2L4(DMF)6] 2(OTf) 2(DMF) (1) promotes the domino reaction of furfural and amines, with loadings as low as 0.01%, under stirring or microwave-assisted conditions to afford the corresponding frameworks in very good to excellent yields. Crystallographic and theoretical studies shed light on the exclusive formation of the trans-diastereoisomers via a 4π-conrotatory electrocyclization process elucidating the key step in the catalytic process
Model selection based algorithm in neonatal Chest EIT
This paper presents a new method for selecting a patient specific forward model to compensate for anatomical variations in electrical impedance tomography (EIT) monitoring of neonates. The method uses a combination of shape sensors and absolute reconstruction. It takes advantage of a probabilistic approach which automatically selects the best estimated forward model fit from pre-stored library models. Absolute/static image reconstruction is performed as the core of the posterior probability calculations. The validity and reliability of the algorithm in detecting a suitable model in the presence of measurement noise is studied with simulated and measured data from 11 patients.
The paper also demonstrates the potential improvements on the clinical parameters extracted from EIT images by
considering a unique case study with a neonate patient undergoing computed tomography imaging as clinical indication prior to EIT monitoring. Two well-known image reconstruction techniques, namely GREIT and tSVD, are implemented to create the final tidal images. The impacts of appropriate model selection on the clinical extracted parameters such as center of ventilation and silent spaces are investigated.
The results show significant improvements to the final reconstructed images and more importantly to the clinical EIT parameters extracted from the images that are crucial for decision-making and further interventions
Polynuclear ampyrone based 3d coordination clusters
The use of the monoanionic Schiff base ligand (E)-4-(2-hydroxybenzylideneamino)-2,3-dimethyl-1-phenyl-1,2-dihydropyrazol-5-one in transition (Co, Ni and Cu) coordination chemistry yields mono-, tetra- and pentanuclear Coordination Clusters with different structural motifs. An organic transformation occurs in the ligand in the Cu compound for which theoretical studies are presented. Solution studies, topological issues and magnetic studies are discussed. The present results demonstrate the richness of the coordination chemistry of this monoprotic organic ligand, which promotes the formation of high-nuclearity CC
Intramuscular vaccination of Atlantic lumpfish (Cyclopterus lumpus L.) induces inflammatory reactions and local immunoglobulin M production at the vaccine administration site
Atlantic lumpfish were vaccinated by intramuscular (im) or intraperitoneal (ip) injection with a multivalent oil‐based vaccine, while control fish were injected with phosphate‐buffered saline. Four lumpfish per group were sampled for skin/muscle and head kidney tissue at 0, 2, 7, 21 and 42 days post‐immunization (dpi) for histopathology and immunohistochemistry (IHC). Gene expressions of secretory IgM, membrane‐bound IgM, IgD, TCRα, CD3ε and MHC class IIβ were studied in tissues by using qPCR. Im. vaccinated fish showed vaccine‐induced inflammation with formation of granulomas and increasing number of eosinophilic granulocyte‐like cells over time. On IHC sections, we observed diffuse intercellular staining of secretory IgM at the injection site at 2 dpi, while IgM + cells appeared in small numbers at 21 and 42 dpi. Skin/muscle samples from im. vaccinated fish demonstrated an increase in gene expression of IgM mRNA (secretory and membrane‐bound) at 21 and 42 dpi and small changes for other genes. Our results indicated that im. vaccination of lumpfish induced local IgM production at the vaccine injection site, with no apparent proliferation of IgM + cells. Eosinophilic granulocyte‐like cells appeared shortly after im. injection and increased in numbers as the inflammation progressed.publishedVersio
Estimation of thorax shape for forward modelling in lungs EIT
The thorax models for pre-term babies are developed based on the CT scans from new-borns and their effect on image reconstruction is evaluated in comparison with other available models
Model Selection Based Algorithm in Neonatal Chest EIT
This paper presents a new method for selecting a patient specific forward model to compensate for anatomical variations in electrical impedance tomography (EIT) monitoring of neonates. The method uses a combination of shape sensors and absolute reconstruction. It takes advantage of a probabilistic approach which automatically selects the best estimated forward model fit from pre-stored library models. Absolute/static image reconstruction is performed as the core of the posterior probability calculations. The validity and reliability of the algorithm in detecting a suitable model in the presence of measurement noise is studied with simulated and measured data from 11 patients
Heptanuclear disk-like MII3LnIII4 (M=Ni, Co) coordination clusters: synthesis, structures and magnetic properties
The synthesis, characterization, crystal structures and magnetic properties of isoskeletal heptanuclear disk-like MII 3LnIII 4 coordination clusters with the general formula [CoII 3LnIII 4(µ3- OH)6L6(CF3SO3)](CF3SO3)5] where Ln= Gd (2), Y (3) and [NiII 3LnIII 4(µ3- OH)6L6(CF3SO3)](CF3SO3)5] where Ln= Dy (4), Gd (5), Y (6) are presented. All the compounds are stable in solution as confirmed by ESI-MS. Magnetic studies were performed for compounds 2, 4, 5 and 6 and indicate ferromagnetic coupling while the magnetocaloric properties of 5 are characterized by ΔSm = -15.4 Jkg-1K -1 at T = 5.0 K and Tad = 5.9 K at T = 2.3 K, for µ0ΔH = 7 T
Modulation of σ-Alkane Interactions in [Rh(L2)(alkane)]+ Solid-State Molecular Organometallic (SMOM) Systems by Variation of the Chelating Phosphine and Alkane : Access to η2,η2-σ-Alkane Rh(I), η1-σ-Alkane Rh(III) Complexes, and Alkane Encapsulation
Solid/gas single-crystal to single-crystal (SC-SC) hydrogenation of appropriate diene precursors forms the corresponding σ-alkane complexes [Rh(Cy2P(CH2)nPCy2)(L)][BArF 4] (n = 3, 4) and [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(L)][BArF 4] (n = 5, L = norbornane, NBA; cyclooctane, COA). Their structures, as determined by single-crystal X-ray diffraction, have cations exhibiting Rh···H-C σ-interactions which are modulated by both the chelating ligand and the identity of the alkane, while all sit in an octahedral anion microenvironment. These range from chelating η2,η2 Rh···H-C (e.g., [Rh(Cy2P(CH2)nPCy2)(η2η2-NBA)][BArF 4], n = 3 and 4), through to more weakly bound η1 Rh···H-C in which C-H activation of the chelate backbone has also occurred (e.g., [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(η1-COA)][BArF 4]) and ultimately to systems where the alkane is not ligated with the metal center, but sits encapsulated in the supporting anion microenvironment, [Rh(Cy2P(CH2)3PCy2)][COÅBArF 4], in which the metal center instead forms two intramolecular agostic η1 Rh···H-C interactions with the phosphine cyclohexyl groups. CH2Cl2 adducts formed by displacement of the η1-alkanes in solution (n = 5; L = NBA, COA), [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(κ1-ClCH2Cl)][BArF 4], are characterized crystallographically. Analyses via periodic DFT, QTAIM, NBO, and NCI calculations, alongside variable temperature solid-state NMR spectroscopy, provide snapshots marking the onset of Rh···alkane interactions along a C-H activation trajectory. These are negligible in [Rh(Cy2P(CH2)3PCy2)][COÅBArF 4]; in [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(η1-COA)][BArF 4], σC-H → Rh σ-donation is supported by Rh → σ∗C-H "pregostic" donation, and in [Rh(Cy2P(CH2)nPCy2)(η2η2-NBA)][BArF 4] (n = 2-4), σ-donation dominates, supported by classical Rh(dπ) → σ∗C-H π-back-donation. Dispersive interactions with the [BArF 4]- anions and Cy substituents further stabilize the alkanes within the binding pocket
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