Dynamic contrast-enhanced MRI with Gd-EOB-DTPA for the quantitative assessment of early-stage liver fibrosis induced by carbon tetrachloride in rabbits

PurposeTo explore quantitative parameters obtained by dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) with Gd-EOB-DTPA in discriminating early-stage liver fibrosis (LF) in a rabbit model.Materials and methodsLF was established in 60 rabbits by the injection of 50% CCl₄ oil solution, whereas 30 rabbits served as the control group. All rabbits underwent pathological examination to determine the LF stage using the METAVIR classification system. DCE MRI was performed, and quantitative parameters, including K^trans, K_ep, V_e, V_p and Re were measured and evaluated among the different LF stages using spearman correlation coefficients and receiver operating characteristic curve.ResultsIn all, 24, 25, and 22 rabbits had stage F0, stage F1, and stage F2 LF, respectively. K^trans (r = 0.803) increased, and K_ep (r = −0.495) and Re (r = −0.701) decreased with LF stage progression (P < 0.001), while no significant correlation was found for V_e or V_p. K^trans and Re were significantly different between all LF stage pairs compared (F0 vs. F1, F0 vs. F2, F1 vs. F2, F0 vs. F1-F2, P < 0.05). With the exception of F0 vs. F1, K_ep differed significantly between stages (P < 0.05). The AUC of K^trans was higher than that of other quantitative parameters, with an AUC of 0.92, 0.99, 0.94 and 0.92 for staging F0 vs. F1, F0 vs. F2, F1 vs. F2, and F0 vs. F1-F2, respectively.ConclusionAmong quantitative parameters of Gd-EOB-DTPA DCE MRI, K^trans was the best predictor for quantitatively differentiating early-stage LF.     

Differentiation of myeloma and metastatic cancer in the spine using dynamic contrast-enhanced MRI

Spinal myeloma and metastatic cancer cause similar symptoms and show similar imaging presentations, thus making them difficult to differentiate. In this study, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed to differentiate between 9 myelomas and 22 metastatic cancers that present as focal lesions in the spine. The characteristic DCE parameters, including the peak signal enhancement percentage (SE%), the steepest wash-in SE% during the ascending phase and the wash-out SE%, were calculated by normalizing to the precontrast signal intensity. The two-compartmental pharmacokinetic model was used to obtain K^trans and k_ep. All nine myelomas showed the wash-out DCE pattern. Of the 22 metastatic cancers, 12 showed wash-out, 7 showed plateau, and 3 showed persistent enhancing patterns. The fraction of cases that showed the wash-out pattern was significantly higher in the myeloma group than the metastatic cancer group (9/9 = 100% vs. 12/22 = 55%, P = .03). Compared to the metastatic cancer group, the myeloma group had a higher peak SE% (226% ± 72% vs. 165% ± 60%, P = .044), a higher steepest wash-in SE% (169% ± 51% vs. 111% ± 41%, P = .01), a higher K^trans (0.114 ± 0.036 vs. 0.077 ± 0.028 1/min, P = .016) and a higher k_ep (0.88 ± 0.26 vs. 0.49 ± 0.23 1/min, P = .002). The receiver operating characteristic analysis to differentiate between these two groups showed that the area under the curve was 0.798 for K^trans, 0.864 for k_ep and 0.919 for combined K^trans and k_ep. These results show that DCE-MRI may provide additional information for making differential diagnosis to aid in choosing the optimal subsequent procedures or treatments for spinal lesions.     

Measuring theWW γ vertex in the processep→γϑX

We present a detailed analysis of the processep→γ?X as a means of studying the gauge structure of theWWγ vertex. We find that the differential cross section of highp _T photons offers a sensitive measure of anomalousWWγ couplings. At HERA \((\sqrt s = 314GeV)\) , after several years of running, theWWγ vertex can be measured to δκ_γ ? _?2.0 ^+2.9 and δλ_γ ? _?2.5 ^+3.0 (95% C.L.). Which offers an improvement over existing constraints from direct measurements using associatedWγ production in \(\bar pp\) collisions but is less sensitive than the competing process at HERA,ep→eWX. For a higher energyep collider, LEP-LHC \((\sqrt s = 1.3TeV)\) , theWWγ vertex can be measured to δδκ_γ ? ± 0.4 and δλκ_γ ? ± 0.1 at 95%C.L. which is more sensitive to λ_γ than the processe ⁺ e ^?→W ⁺ W ^? at the LEP200e ⁺ e ^? collider and is comparable to the LEP200 sensitivity to κ_γ. These values are also roughly comparable to the competing processep→eWX at LEP-LHC and to what is expected from associated γW production at the LHC and SSC for κ_γ but they are about half as sensitive to λ_γ as the LHC and SSC.     

Reconstructing very short TE phase rotation spectral data collected with multichannel phased-array coils at 3 T

Phased-array volume coils were used in conjunction with the phase rotation STEAM (PR-STEAM) spectroscopy technique to acquire very short TE data from the anterior cingulate gyrus at 3 T. A method for combining PR-STEAM data from multiple subcoils is presented. The data were acquired from seven healthy participants using PR-STEAM (repetition time/mixing time/echo time=3500/10/6.5 ms, 6 cm³, NEX=128, spectral width=2000 Hz, 2048 complex points, Δφ₁=135°, Δφ₂=22.5°, Δφ₃=112.5° and Δφ_ADC=0°). In addition to the primary metabolites, LCModel fit results suggest that glutathione and glutamate can also be identified with Cramér-Rao lower bounds of 10% or less.     

Hamiltonian analysis of 4-dimensional spacetime in Bondi-like coordinates

We discuss the Hamiltonian formulation of gravity in four-dimensional spacetime under Bondi-like coordinates {v,r,x~a,a=2,3}. In Bondi-like coordinates, the three-dimensional hypersurface is a null hypersurface, and the evolution direction is the advanced time v. The internal symmetry group SO(1,3) of the four-dimensional spacetime is decomposed into SO(1,1), SO(2), and T~±(2), whose Lie algebra so(1,3) is decomposed into so(1,1), so(2), and t~±(2) correspondingly. The SO(1,1) symmetry is very obvious in this type of decomposition, which is very useful in so(1,1) BF theory. General relativity can be reformulated as the four-dimensional coframe(e_μ~I) and connection(ω_μ~(IJ))dynamics of gravity based on this type of decomposition in the Bondi-like coordinate system. The coframe consists of two null 1-forms e~-, e~+and two spacelike 1-forms e~2, e~3. The Palatini action is used. The Hamiltonian analysis is conducted by Dirac's methods. The consistency analysis of constraints has been done completely. Among the constraints, there are two scalar constraints and one two-dimensional vector constraint. The torsion-free conditions are acquired from the consistency conditions of the primary constraints about π_(IJ)~μ. The consistency conditions of the primary constraints π_(IJ)~0=0 can be reformulated as Gauss constraints. The conditions of the Lagrange multipliers have been acquired. The Poisson brackets among the constraints have been calculated. There are 46 constraints including 6 first-class constraints π_(IJ)~0=0 and 40 second-class constraints. The local physical degrees of freedom is 2.The integrability conditions of Lagrange multipliers n_0, l_0, and e_0~A are Ricci identities. The equations of motion of the canonical variables have also been shown.     

Co-reduction synthesis of new LnxSb2−xS3 (Ln: Nd, Lu, Ho) nanomaterials and investigation of their physical properties

New Ln_xSb_2−xS₃ (Ln: Lu³⁺, Ho³⁺, Nd³⁺)-based nanomaterials were synthesized by a co-reduction method. Powder XRD patterns indicate that the Ln_xSb_2−xS₃ crystals (Ln=Lu³⁺, Ho³⁺, x=0.00−0.1 and Ln=Nd³⁺, x=0.00−0.08) are isostructural with Sb₂S₃. SEM images show that doping of Lu³⁺ and Ho³⁺ ions in the lattice of Sb₂S₃ results in nanorods while that in Nd³⁺ leads to nanoflowers. UV-vis absorption and emission spectroscopy reveal mainly electronic transitions of the Ln³⁺ ions in case of Ho³⁺ and Nd³⁺ doped nanomaterials. Emission spectra show intense transitions from excited to ground state of Ln³⁺. Emission spectra of doped materials, in addition to the characteristic red emission peaks of Sb₂S₃, show other emission bands originating from f-f transitions of the Ho³⁺ ions. TGA curves indicated that Sb₂S₃ has the highest thermal stability. The electrical conductance of Ln-doped Sb₂S₃ is higher than undoped Sb₂S₃, and increase with temperature.     

Evaluation of the Integrated Cross Sections of Reactions of Exclusive Pion and Kaon Electroproduction off Protons in the Resonance Region at Photon Virtualities from 5 to 12 GeV<Superscript>2</Superscript>

The integrated cross sections of the ep → eπ⁺n, ep → eπ⁰p, ep → eK⁺Λ, and ep → eK⁺Σ⁰ reactions are evaluated in the energy range of nucleon resonance excitation at photon virtualities Q² from 5 to 12 GeV². These exclusive channels will be explored at photon virtualities Q² > 5 GeV² for the first time in future experiments with the CLAS12 detector. The cross-section evaluation is based on the extrapolation of exclusive contributions to the inclusive structure functions F₁ and F₂ from a region of Q² < 5 GeV², in which the experimental data are available, to the region of higher Q². This evaluation of cross sections is of particular importance in the development of the program of experiments with the CLAS12 detector for studying the structure of the ground and excited nucleon states, which may reveal the dynamics of strong interactions in the nonperturbative regime.     

A model of deep inelastic polarized electroproduction

A realistic phenomenological model combining parton/QCD ideas with lower energy SU(6) constraints is proposed for the shape and evolution of the leading spin-dependent structure function G^ep(x, Q²) in polarized electroproduction. Close's broken-SU(6) ansatz is used to relate appropriately defined polarized quark-parton distribution densities to unpolarized ones at the matching momentum scale Q² = Q₀². The differences between spin and helicity distribution densities as well as the complications due to perturbative QCD and parton k_T (with related target-mass) effects are taken into account. Evolution to higher (>10 GeV²) values of Q² (where target-mass effects can be neglected) yields experimentally testable numerical predictions that are presented through various plots. The value of Q₀ is self-consistently determined to be about 0.5 GeV.     

The effect of Gd3+ and Cd2+ substitution on magnetization of copper ferrite

Polycrystalline compositions of soft ferrite system, Cd_xCu_1−xFe_2−yGd_yO₄ (X=0.00, 0.20, 0.40, 0.60, 0.80 and 1.00; y=0.00, 0.10 and 0.30) were prepared by standard ceramic method. X-ray diffraction study show formation of single phase cubic spinel ferrite for the compositions X⩾0.20 and tetragonal nature for compositions X=0.00, for all values of Gd³⁺ (y=0.00, 0.10 and 0.30) concentration. Saturation magnetization and magnetic moments were found to be increasing with cadmium concentration up to X=0.40, for all values of Gd³⁺ content, obeying Neel's two sublattice model and decreases thereafter, showing existence of non-collinear spin interaction. The Gd³⁺ substitution results into reaction in the magnetic moments. This is due to occupancy of Gd³⁺ ion on octahedral (B) site, resulting into dilution in the magnetization of B sublattices. The Curie temperatures for all compositions are found to be decreasing with substitution of Cd²⁺ concentration. This is attributed to the occupancy of cadmium on tetrahedral (A) site, causing dilution in the inter site magnetic interaction. The temperature dependence of AC susceptibility is also studied and its behaviour is explained on the basis of domain structure.     

Differentiation of bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone with multiparametric MRI

PurposeTo investigate the diagnostic utilities of imaging parameters derived from T1-weighted imaging (T1WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to differentiate bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone.Materials and methodsThirty-six lesions from 36 patients with prostate cancer were analyzed with T1WI, DWI, and DCE-MRI. The lesions were classified in the bone metastases (n = 22) and benign red marrow depositions (n = 14). Lesion-muscle ratio (LMR), apparent diffusion coefficient (ADC), volume transfer constant (K^trans), reflux rate (Kep), and volume fraction of the extravascular extracellular matrix (Ve) values were obtained from the lesions. The imaging parameters of the both groups were compared using the Mann-Whitney U test, receiver operating characteristics (ROC) curves were analyzed. For the ROC curves, area under the curves (AUCs) were compared.ResultsThe ADC, K^trans, K_ep, and V_e values of bone metastases were significantly higher than those of benign red marrow depositions (Mann-Whitney U test, p < 0.05). However, there was no significant difference in LMR between the two groups (Mann-Whitney U test, p = 0.360). The AUCs of K^trans_, K_ep, ADC, V_e, and LMR were 0.896, 0.844, 0.812, 0.724, and 0.448, respectively. In the pairwise comparison of ROC curves, the AUCs of K^trans and K_ep was significantly higher than LMR.ConclusionsK^trans, K_ep, V_e, and ADC values can be used as imaging tools to differentiate bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone.     

119Sn Mössbauer, NMR (1H, 13C and 119Sn) and infrared study of tetracoordinated tin(IV) complexes with 4-[((E)-1-{2-hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]benzoates

A series of organotin(IV) complexes of composition R₃Sn[O₂CC₆H₄{N= C(H)C₆H₃-2-OH(N=NC₆H₄R)}-p] (R = Ph or Bz; R = H, 2-CH₃, 3-CH₃, 4-CH₃) have been investigated by ¹¹⁹Sn Mössbauer, ¹H, ¹³C, ¹¹⁹Sn NMR and IR spectroscopic techniques. ¹¹⁹Sn Mössbauer data indicated a distorted tetrahedral geometry for the triphenyltin(IV) complexes while the tribenzyltin complexes exhibit a distorted trigonal bipyramidal coordination geometry with equatorial benzyl groups and the axial positions occupied by an O atom from the carboxylate ligand and the O atom from the water ligand. The ¹¹⁹Sn-NMR chemical shifts confirm that the Sn atom in triorganotin complexes is four-coordinate in CDCl₃ solution.     

Observation and analysis of the Xe−I collisional-pair photoassociation spectrum

The interpretation of the photoassociation spectrum arising in collisions of Xe and I atoms is refined with allowance for new data concerning the interaction potential of Xe and I collisional pairs. Spectroscopic constants for the XeI(B) state are determined:R′ _e =3.264961 Å,D′ _e =33,289.05 cm^?1,w′ _e =113.867826 cm^?1, andw′ _e x′ _e =0.238304 cm^?1.     

Complex Regge poles and high energy scattering data

For the high energy data on σ_tot^pp the proton-proton total cross section, and on ?, the ratio of real to imaginary part of the forward elastic amplitude, including the recent ISR results, an excellent fit is obtained with P, P', ω Regge poles plus a pair of complex conjugate Regge poles. The complex poles describe the possible oscillatory behavior of the quantities σ_tot^pp and ?. The physical meaning of these complex poles and extrapolation to future measurements of the above quantities are discussed.     

A new molecular C60 complex with bis(methylenedithio)tetrathiafulvalene (BMDT-TTF): Synthesis, crystal structure, and properties

A new molecular C₆₀ complex of the composition (BMDT-TTF) · C₆₀ · 2CS₂ (I) with the bis(methylenedithio)tetrathiafulvalene (BMDT-TTF) organic donor is synthesized. The molecular and crystal structures of this complex are determined by x-ray diffraction. The (BMDT-TTF) · C₆₀ · 2CS₂ (I) compound crystallizes in a monoclinic crystal system. The main crystal data are as follows: a=13.550(5) Å, b=9.964(7) Å, c=17.125(8) Å, β=99.52(4)°, V=2280(2) ų, M=1229.45, and space group P2₁/m. Crystals of I have a layered structure: layers consisting of C₆₀ molecules alternate with layers composed of BMDT-TTF and CS₂ molecules. It is found that, in complex I, the donor and C₆₀ molecules are linked through the shortest contacts, which leads to a change in the molecular geometry of BMDT-TTF. The donor molecules in a crystal layer are characterized by the shortest S...S contacts. The IR data indicate the electroneutrality of the fullerene molecule. The electrical conductivity of (BMDT-TTF) · C₆₀ · 2CS₂ single crystals is measured using the four-point probe method at room temperature: σ_RT=2×10^?5 Ω^?1 cm^?1.     

Pr-substituted W-type barium ferrite: Preparation and electromagnetic properties

The W-type ferrites doped with Pr³⁺, BaCoNiPr_xFe_16−xO₂₇ (x=0-0.20), were prepared by a sol-gel method. The structure and electromagnetic properties of the samples are studied using powder X-ray diffraction, field emission scanning electron microscope, vibrating sample magnetometer and vector network analyzer. All the samples are hexagonal platelet-like W-type barium ferrite. These synthesized samples exhibit paramagnetism and strong magnetism. The saturation magnetization (Ms) increases with the increase of Pr³⁺ content. The real part of complex permittivity (ε′) decreases and the imaginary part (ε″) increases with Fe³⁺ replaced by Pr³⁺. The imaginary part of complex permittivity (μ″) increases and the real part (μ′) decreases after Pr³⁺ is doped. Furthermore, the doped Pr³⁺ improves the microwave absorbency.     

Synthesis, crystal structure, dielectric and optical properties of a new rare earth double perovskite: Ca2CeNbO6

In order to develope and understand the phenomena involved in producing advanced materials, a rare earth double perovskite oxide calcium cerium niobate, Ca₂CeNbO₆ (CCN) is synthesized for the first time. The x-ray diffraction pattern of CCN at room temperature (300K) shows orthorhombic perovskite structure, with the lattice parameters, a=9.36Å, b=6.61Å and c=5.88Å and α=β=γ= 90°. A scanning electron micrograph shows the formation of grains with average size ∼2μm. Impedance spectroscopy and Fourier transform infrared spectroscopy are applied to investigate the dielectric and optical properties of CCN. The frequency-dependent electrical data are analyzed in the framework of the conductivity and modulus formalisms. The experimental data of real part of dielectric permittivity (ε′) and imaginary part of electric modulus (M″) are fitted with Davidson-Cole equation to explore the idea of dielectric relaxation (conduction) mechanism in CCN. The frequency-dependent conductivity spectra follow a power law. The scaling behaviour of imaginary electric modulus (M″) suggests that the relaxation describes the same mechanism at various temperatures.     

On the difference of scaling violations for proton and neutron targets

It is shown that the different Q² dependence for F₁^ep and F₁^ep, as recently observed at SLAC, is compatible with field theoretic expectations.     

Electromagnetic and microwave absorbing properties of Co2Z-type hexaferrites doped with La

Z-type ferrites doped with La³⁺, Ba_3−xLa_xCo₂Fe₂₄O₄₁ (x=0.00-0.30), were prepared by sol-gel method. The effect of the substitution La³⁺ rare-earth ions for Ba²⁺ ions on the microstructure, complex permeability, permittivity and microwave absorption of the samples was investigated. The results show that the major phase of the ferrites changed to Z-phase when sintering temperature was 1250 °C for 5 h. With the increase of the substitution ratio of La³⁺ ions from 0.0 to 0.3, the lattice parameters a and c increased gradually, which resulted in the change of the particle shape and size. The data of magnetism showed that the addition of La³⁺ ions make the ferrite a better soft magnetic material due to increase of magnetization (σ_s) and decrease of coercivity (H_c). The La³⁺ ions doped in the ferrite not only improved complex permeability and complex permittivity, but also microwave absorbency.     

Structure and magnetotransport properties of the new quasi-two-dimensional molecular metal β″-(BEDT-TTF)4H3O[Fe(C2O4)3] · C6H4Cl2

The β″-(BEDT-TTF)₄A^I[M^III(C₂O₄)₃] · G(A^I=NH ₄ ⁺ , H₃O⁺, K⁺, Rb⁺; M^III=Fe, Cr; G = “guest” solvent molecule) family of layered molecular conductors with magnetic metal oxalate anions exhibits a pronounced dependence of the conducting properties on the type of neutral solvent molecules introduced into the complex anion layer. A new organic dichlorobenzene (C₆H₄Cl₂)-containing conductor of this family, namely, β″-(BEDT-TTF)₄H₃O[Fe(C₂O₄)₃] · C₆H₄Cl₂, is synthesized. The structure of the synthesized single crystals studied by X-ray diffraction is characterized by the following parameters: a = 10.421(1) Å, b= 19.991(2) Å, c= 35.441(3) Å, β = 92.87(1)°, V= 7374(1) ų, space groupC2/c, and Z = 4. In the temperature range 0.5&;2-300 K, the conductivity of the crystals is metallic without changing into a superconducting state. The magnetotransport properties of the crystals are examined in magnetic fields up to 17 T at T = 0.5 K. In fields higher than 10 T, Shubnikov-de Haas oscillations are detected, and the Fourier spectrum of these oscillations contains two frequencies with maximum amplitudes of about 80 and 375 T. The experimental results are compared with the related data obtained for other phases of this family. The possible structural mechanisms of the effect of a guest solvent molecule on the transport properties of the β″-(BEDT-TTF)₄A^I[M^III(C₂O₄)₃] · G crystals are analyzed.