Apparent Dispersion Research Articles

Low-temperature sintering BCZT-Dy ceramics with low strain hysteresis for actuator application

Ba(Cu0.5W0.5)O3 (BCuW)-doped [(Ba0.85Ca0.15)1-xDyx](Zr0.1Ti0.9)O3 (BCZT-xDy, x = 0.001, 0.03) ceramics were prepared by conventional ceramic processing via low-temperature sintering technique. Rather pure perovskite structure and densified morphology with irregular nearly spherical-shape grains are achieved in all ceramics due to liquid-phase sintering. All BCuW-doped BCZT-xDy ceramics present apparent dielectric frequency dispersion and relaxor ferroelectric characteristic due to ion substitution and adding BCuW. The ceramics prepared at optimized sintering temperatures have rather large strain and small strain hysteresis, showing prospect application in piezoelectric high-precision actuators.

Accounting for ground-motion uncertainty in empirical seismic fragility modeling

Seismic fragility models provide a probabilistic relation between ground-motion intensity and damage, making them a crucial component of many regional risk assessments. Estimating such models from damage data gathered after past earthquakes is challenging because of uncertainty in the ground-motion intensity the structures were subjected to. Here, we develop a Bayesian estimation procedure that performs joint inference over ground-motion intensity and fragility model parameters. When applied to simulated damage data, the proposed method can recover the data-generating fragility functions, while the traditionally used method, employing fixed, best-estimate, intensity values, fails to do so. Analyses using synthetic data with known properties show that the traditional method results in flatter fragility functions that overestimate damage probabilities for low-intensity values and underestimate probabilities for large values. Similar trends are observed when comparing both methods on real damage data. The results suggest that neglecting ground-motion uncertainty manifests in apparent dispersion in the estimated fragility functions. This undesirable feature can be mitigated through the proposed Bayesian procedure.

Time-dependent dispersion coefficients for the evolution of displacement fronts in heterogeneous porous media

We present an approach for quantifying displacement fronts in heterogeneous porous media based on the concept of time-dependent apparent dispersion coefficients. The concept of constant asymptotic macrodispersion generally overestimates the area swept by a displacement front and leads to unrealistic upstream dispersion. We show that the large-scale front spreading can be captured by a one-dimensional advection–dispersion equation that is parameterized by a suitably chosen temporally evolving dispersion coefficient. For purely advective front spreading, we derive an analytical expression based on a predictive continuous time random walk approach, which applies to highly heterogeneous porous media. This analysis elucidates the variability of solute travel times as the key longitudinal spreading mechanism. It shows that the evolution of dispersion can be captured as the sum of exponentials that decay on two dominant time scales. In a particle-based picture, these scales mark the short time at which transported particles start exploring the flow variability and the large time at which the slowest particles start decorrelating their transport velocity. Based on these insights, we propose a heuristic formula that accounts for the impact of local-scale dispersion as an additional decorrelation mechanism. The heuristic expression for the longitudinal dispersion coefficient captures solute spreading for a broad range of Péclet numbers and heterogeneity variances. The proposed approach is tested against direct numerical simulations. It provides a robust and fast method for quantifying the evolution of displacement fronts in heterogeneous porous media with possible applications, for example, in groundwater contamination modelling, underground gas storage, and geothermal energy production.

Studying the Structure‐Reactivity Relationship of CuO/CeO2 for Catalytic Soot Particulate Combustion: On the Monolayer Dispersion Threshold Effect

AbstractTo elucidate structure‐reactivity relationship and prepare improved catalysts for soot combustion, a series of CuO/CeO2 with different loadings have been fabricated by the impregnation method. With XRD and XPS extrapolation methods, it is disclosed that CuO disperses finely on the CeO2 support to form a monolayer with a capacity around 1.06 mmol 100 m−2, which equals to 2.9 wt. % CuO loading. Below this capacity, CuO is in a sub‐monolayer state. However, above this capacity, CuO micro‐crystallites are formed, and co‐exist with the monolayer CuO. By increasing CuO loading, soot combustion activity of the catalysts increases as well until it reaches the monolayer dispersion capacity. Further increasing the CuO loading to 5 % decreases the activity slightly, and then remains constant. Therefore, an apparent monolayer dispersion threshold effect is observed for soot combustion on CuO/CeO2 catalysts. It is found that the amount of surface‐active O2− sites plays critical role for the catalytic activity. To obtain the most active CuO/CeO2 catalyst, a monolayer amount of CuO should be loaded on the supports.

Identification of Luminal A breast cancer by using deep learning analysis based on multi-modal images.

To evaluate the diagnostic performance of a deep learning model based on multi-modal images in identifying molecular subtype of breast cancer. A total of 158 breast cancer patients (170 lesions, median age, 50.8 ± 11.0 years), including 78 Luminal A subtype and 92 non-Luminal A subtype lesions, were retrospectively analyzed and divided into a training set (n = 100), test set (n = 45), and validation set (n = 25). Mammography (MG) and magnetic resonance imaging (MRI) images were used. Five single-mode models, i.e., MG, T2-weighted imaging (T2WI), diffusion weighting imaging (DWI), axial apparent dispersion coefficient (ADC), and dynamic contrast-enhanced MRI (DCE-MRI), were selected. The deep learning network ResNet50 was used as the basic feature extraction and classification network to construct the molecular subtype identification model. The receiver operating characteristic curve were used to evaluate the prediction efficiency of each model. The accuracy, sensitivity and specificity of a multi-modal tool for identifying Luminal A subtype were 0.711, 0.889, and 0.593, respectively, and the area under the curve (AUC) was 0.802 (95% CI, 0.657- 0.906); the accuracy, sensitivity, and AUC were higher than those of any single-modal model, but the specificity was slightly lower than that of DCE-MRI model. The AUC value of MG, T2WI, DWI, ADC, and DCE-MRI model was 0.593 (95%CI, 0.436-0.737), 0.700 (95%CI, 0.545-0.827), 0.564 (95%CI, 0.408-0.711), 0.679 (95%CI, 0.523-0.810), and 0.553 (95%CI, 0.398-0.702), respectively. The combination of deep learning and multi-modal imaging is of great significance for diagnosing breast cancer subtypes and selecting personalized treatment plans for doctors.

117 Combining Large Broiler Populations into a Single Genomic Evaluation: Dealing with Genetic Divergence

Abstract Combining populations that diverged at some point is a common practice, especially in poultry, where generation intervals are short and genetic evaluations should be available often. This study assessed whether combining large, divergent broiler populations into one genomic evaluation is feasible and the best strategy for doing that in single-step GBLUP. The pedigree for populations 1 and 2 included 397,954 and 411,780 animals, of which 154,911 and 168,429 were genotyped. Phenotypes for body weight (g), carcass yield (%), mortality (0-1), and feet health (0-6) were available for 397,954 animals in population 1 and 411,780 in population 2. A four-trait model was used in the analyses, and the genetic differences between the two populations were modeled in different ways: M1) included an extra fixed effect that accounted for population origin; M2) added origin-specific fixed effects, where the animal origin was concatenated with all fixed effects in the model. The two models were compared against a conventional model without accounting for the animal origin as a fixed effect (M0). Unknown parent groups (UPG) were fit to account for the genetic differences in M0, M1, and M2; therefore, they were set based origin population of the animal and sex. The models were evaluated based on accuracy, bias, and dispersion from the linear regression (LR) method and predictive ability (PA), where GEBV in the reduced data was compared against phenotypes adjusted for fixed effects. Validations were done separately in single and multi-populations to better assess the benefits of combining the two populations. Overall, the accuracy obtained by PA was less than by LR. No apparent accuracy, PA, bias, and dispersion differences were observed among the multi-population models across all traits. This was also true when comparing validation parameters in a multi-population against the ones from a single population. However, we observed that animals from one population were always superior to the other. A multi-trait model was applied, treating the same trait in each population differently. Genetic correlations between the same trait in different populations were moderate to low, suggesting that the two lines should possibly be evaluated separately. Defining whether populations should be combined in a single evaluation may go beyond validation parameters. Identifying if traits are the same across populations is crucial for the feasibility of combined evaluations.

Physicochemical characterization and environmental stability of a curcumin-loaded Pickering nanoemulsion using a pea protein isolate-dextran conjugate via the Maillard reaction

This study investigated pea protein isolate (PPI) and dextran (DX) conjugates produced via the Maillard reaction as Pickering stabilizers for various food applications. The results found that as heating time increased (0–5 h), the grafting degree heightened. The PPI-DX conjugate exhibited a rough porous surface in contrast to native PPI, accompanied by changes in molecular weight and secondary structure. Additionally, the aggregation of low-solubility PPI was partially inhibited due to the contribution of increased solubility and reduced surface hydrophobicity by glycation. Curcumin-loaded Pickering nanoemulsions stabilized with PPI-DX had smaller droplets and higher curcumin encapsulation (greater than80 %) than PPI-stabilized nanoemulsions. PPI-DX adsorbed on the interface showed improved physical stability compared to PPI alone, even after various pH conditions and three heat treatments. The nanoemulsion stabilized with PPI-DX demonstrated improved apparent viscosity and dispersion stability. These findings highlight the effectiveness of PPI-DX conjugates as stabilizers for developing stable and functional Pickering nanoemulsions.

Correction to: Apparent dispersion in pulsar braking index measurements caused by timing noise

Correction to: Apparent dispersion in pulsar braking index measurements caused by timing noise

On the apparent dispersion coefficient of the equilibrium dispersion model: An asymptotic analysis

To model chromatography, researchers have developed several approaches. These cover a broad range of applications and, depending on the assumptions adopted, have different levels of accuracy. In general, the most suitable modelling approach is the simplest that can describe a process with the desired accuracy. A model that often meets this criterion is the equilibrium dispersion model (EDM). This features one mass balance equation per analyte, including an axial dispersion term, and assumes the analyte concentrations in the mobile and stationary phases to be in local equilibrium. To account for the finite mass transfer rate between the phases, the model employs an apparent dispersion coefficient. Two expressions are available for this coefficient, one being used much more frequently than the other. In this paper, we aimed to clarify which one should be favoured. A desirable feature of simple models is that they can be derived from more general ones with appropriate physical assumptions and rigorous mathematical methods. Thus, to answer our research question, we derived the EDM from the more general pore diffusion model (POR), using an asymptotic method. The expression obtained for the apparent dispersion coefficient does agree with one of the two reported in the literature – the less frequently used. To test the validity of this expression, we simulated elution profiles using the two versions of the EDM and compared the results against those from the POR model. The simulations were conducted in the range where the POR and EDM models should be essentially equivalent, their results confirming the outcome of the asymptotic analysis. This work offers a solid theoretical grounding for the EDM, clarifies which formulation of the model is correct, and provides usable applicability conditions for the model.

A seismic elastic moduli module for the measurements of low-frequency wave dispersion and attenuation of fluid-saturated rocks under different pressures

Knowledge about the seismic elastic modulus dispersion, and associated attenuation, in fluid-saturated rocks is essential for better interpretation of seismic observations taken as part of hydrocarbon identification and time-lapse seismic surveillance of both conventional and unconventional reservoir and overburden performances. A Seismic Elastic Moduli Module has been developed, based on the forced-oscillations method, to experimentally investigate the frequency dependence of Young's modulus and Poisson's ratio, as well as the inferred attenuation, of cylindrical samples under different confining pressure conditions. Calibration with three standard samples showed that the measured elastic moduli were consistent with the published data, indicating that the new apparatus can operate reliably over a wide frequency range of f∈[1–2000, 106] Hz. The Young's modulus and Poisson's ratio of the shale and the tight sandstone samples were measured under axial stress oscillations to assess the frequency- and pressure-dependent effects. Under dry condition, both samples appear to be nearly frequency independent, with weak pressure dependence for the shale and significant pressure dependence for the sandstone. In particular, it was found that the tight sandstone with complex pore microstructure exhibited apparent dispersion and attenuation under brine or glycerin saturation conditions, the levels of which were strongly influenced by the increased effective pressure. In addition, the measured Young's moduli results were compared with the theoretical predictions from a scaled poroelastic model with a reasonably good agreement, revealing that the combined fluid flow mechanisms at both mesoscopic and microscopic scales possibly responsible for the measured dispersion.

Critical role of lattice vacancies in A1-site induced by Ca2+-doping on relaxor behavior and electric properties in tungsten bronze Ba2NaNb5O15 ferroelectrics

Constructing relaxor ferroelectric for tetragonal tungsten bronze (TTB) compounds to server the urgent demand of energy storage for an high-power discharge capacitors is important, but the huge challenge of achieving significant breakthrough still lies in the unclear nature of relaxation compared with perovskite structure. In present work, the TTB-type Ba2CaxNa1-2xNb5O15 (BCNN, 0.1 ≤ x ≤ 0.5) ceramics were thoroughly investigated the variation of dielectric and ferroelectric properties accompanying with A1-site crystal vacancies induced by introducing Ca2+. With increasing of Ca2+ concentration, the distortion of NbO6 polar unit was alleviated due to the lattice shrinks arising from the higher lattice vacancies in A1 sites and smaller radius of Ca2+, as confirmed by XRD and Raman spectra. Analyses of I–V characteristics for BCNN ceramics indicate that conductive behavior is dominated by the space charge limited conduction, which associated with the oxygen vacancies arising from the evaporate of sodium element during high-temperature sintering. It is found that the space charge plays a crucial role in the unique dielectric and ferroelectric characteristics. Besides the typical phase transitions from ferroelectric (4 mm) to paraelectric (4/mmm), low-temperature dielectric anomaly derived from the freeze-out of polarizability caused by distorted polar octahedron. The apparent dielectric dispersion and extremely higher dielectric constant at lower frequencies arise from the pace charge polarization confirmed the rationality of the heterostructure by electric impedance spectroscopy (EIS). The ferroelectricity is associated with the insulation leakage from the space charge, besides the ferroelectric domain switching, that further confirmed by the conduction mechanism. Moreover, the sintered BCNN ceramics displayed the homogeneous equiaxed grain together with uniform distribution, which endows an excellent optical transmittance of BCNN ceramics at x = 0.5 and far exceeds that of iso-structural SCNN ceramics. The above results not only confirm the critical role of modulation in A1-site for constructing relaxor, but also delivers a new path into the design dielectric materials with ultrahigh transparent performance.

Engineering, Geophysical Investigation of a Multistory Building, at Hilla, Iraq, Utilizing the MASW Method

The Multi-Channel Method for Surface Waves (MASW) was used to estimate the average velocity of shear waves in order to construct an engineering structure and its relationship to bearing capacity, foundation depth and soil thickness in this construct in the center of Hilla city. Active MASW was used in this study which allows us to measure the apparent dispersion curve or the phase velocity within the frequency range from 5 to 70 Hz, which gives information about the shallow layers (25-50 m) and depending on the ground hardness and spreading length. Where it was found that this area consists of two layers and each layer has a shear velocity, as the first layer has shear velocity (171.891) m/sec and the depth (8.244) m and the second layer has shear velocity (274.788) m/sec and the maximum bearing capacity value relative to the depth of the foundation is 1, 2 and 3 is 4.46, 5.27 and 5.96 T/m2 respectively. According to this study, this area is suitable for constructing an engineering structure on it.

Apparent dispersion in pulsar braking index measurements caused by timing noise

ABSTRACT Stochastic temporal wandering of the spin frequency ν of a rotation-powered pulsar (i.e. the achromatic component of timing noise unrelated to interstellar propagation) affects the accuracy with which the secular braking torque can be measured. Observational studies confirm that pulsars with anomalous braking indices $\vert n \vert = \vert \nu \ddot{\nu } / \dot{\nu }^2 \vert \gg 1$ exhibit elevated levels of timing noise, where an overdot symbolizes a derivative with respect to time. Here it is shown, through analytic calculations and Monte Carlo simulations involving synthetic data and modern Bayesian timing techniques, that the variance 〈n2〉 of the measured n scales with the square of the timing noise amplitude $\sigma _{\ddot{\nu }}$ . The anomalous regime 〈n2〉 ≫ 1 corresponds to $\sigma _{\ddot{\nu }}^2 \gg 10^{-60} (\gamma _{\ddot{\nu }}/10^{-6} \, {\rm s^{-1}})^2 (\dot{\nu } / 10^{-14} \, {\rm Hz \, s^{-1}})^4 (\nu / 1 \, {\rm Hz})^{-2} (T_{\rm obs} / 10^8 \, {\rm s}) \, {\rm Hz}^2{\rm s}^{-5 }$ , where $\gamma _{\ddot{\nu }}$ is a stellar damping time-scale, and Tobs is the total observing time. When the inequality in the earlier condition is reversed, n is dominated by the secular braking torque, and timing measurements return n ∼ 3, if the secular braking torque is electromagnetic. The variance 〈n2〉 is greater, when the stochastic process driving spin fluctuations differs from the red noise model (e.g. power-law spectral density) assumed in the timing solution.

Triple-attention interaction network for breast tumor classification based on multi-modality images

Breast cancer can be diagnosed using medical imaging. Classification performance of medical imaging can be improved by multi-modality image fusion. However, existing fusion algorithm fail to consider the importance of modality interactions and cannot fully utilize multi-modality information. Attention mechanisms can effectively explore and combine multi-modality information. Thus, we propose a novel triple-attention interaction network for breast tumor classification based on diffusion-weighted imaging (DWI) and apparent dispersion coefficient (ADC) images. A triple inter-modality interaction mechanism is proposed to fully fuse the multi-modality information. Three modal interactions were performed through the developed inter-modality relation module, channel interaction module, and multi-level attention fusion module to explore the correlation, complementary, and discriminative information, respectively. Additionally, we introduce a novel dual parallel-attention module for the incorporation of spatial and channel attention to improve the discriminative ability of single-modality features. Using these mechanisms, the proposed algorithm can mine and explore useful multi-modality information fully, to improve classification performance. Experimental results demonstrate that our algorithm outperforms other multi-modality fusion algorithm, and extensive ablation studies were conducted to verify the advantages of our algorithm. The area under the receiver operating characteristic curve, accuracy, specificity, and sensitivity were 90.5%, 89.0%, 85.6%, and 92.4%, respectively.

Multiple directional DWI combined with T2WI in predicting muscle layer and Ki-67 correlation in bladder cancer in 3.0-T MRI.

To investigate the value of 3.0T MRI multi-directional diffusion-weighted imaging (DWI) combined with T2WI morphological features and lesion distribution in preoperative prediction of muscle layer invasion of bladder cancer (BC) and the correlation with postoperative Ki-67. This retrospective study enrolled patients with BC between 2019 and 2021. Patients with muscular invasive bladder cancer (MIBC) or non-muscular invasive BC (NMIBC) were also analyzed by preoperative 3.0T MRI aFostic efficacy. A total of 186 patients were enrolled. About 27 patients with MIBC (35 lesions in total) and 62 with NMIBC (99 lesions in total). We found the tumor with a larger size, a wide base, and a smaller apparent dispersion coefficient (ADC) value and normalized ADC(nADC) value, without a stalk, presenting a greater risk of muscle invasion. ADC value, nADC value, maximum diameter, and stalk were independently associated with muscle invasion. Lesions located at the bladder fundus or involvement of multiple sites were independently associated with muscle invasion compared to the bladder body. In combination with morphological features, the AUCs of ADC and nADC showed accuracies of 0.925 and 0.947-0.951, respectively. TADC and nTADC showed the best diagnostic efficacy in multiple respects. KI-67 LI was negatively correlated with ADC and nADC values. This is the first report in which we found Multi-directional DWI combined with T2WI in 3.0T MRI can be used to predict the muscle layer invasion of bladder cancer. ADC values reflect the muscular invasion of bladder cancer and show a moderate negative correlation with Ki-67. It is especially suitable for bladder cancer patients with renal insufficiency or tumor recurrence.

Loss of cervical sagittal alignment worsens the cervical spinal lesions in patients with Hirayama disease.

To quantify the cervical sagittal alignment in patients with Hirayama disease (HD) and to investigate the effect of loss of cervical sagittal alignment upon the cervical spinal lesions in HD. Cervical sagittal alignments were measured in 253 HD patients and 63 healthy subjects by C2-C7 Cobb and a modified method of Toyama et al. Motor unit number estimation (MUNE) was performed in bilateral abductor pollicis brevis (APB) in all HD patients, and 31 patients further underwent cervical diffusion tensor imaging (DTI). Compared with healthy subjects, HD patients showed lower C2-C7 Cobb (P < 0.05), and 83.4% patients showed loss of cervical lordosis (cervical straight or kyphosis), which was greater than healthy subjects (55.6%, P < 0.05). Compared with lordotic/straight group, patients with cervical kyphosis showed lower MUNE values and greater single motor unit potential (SMUP) in bilateral APB, and higher apparent dispersion coefficient (ADC) and lower fractional anisotropy were observed at C4/C5 level in the latter than the former (P < 0.05). C2-C7 Cobb was associated with both C4/C5 ADC and bilateral SMUP (P < 0.05). Most HD patients showed loss of cervical sagittal alignments, and both MUNE and DTI detections demonstrated a positive correlation between loss of cervical sagittal alignments and cervical spinal lesions in HD. These findings supported that loss of cervical sagittal alignments may worsen motor impairments in HD. Therefore, it is necessary for clinicians to be aware of restoring cervical sagittal alignments during HD treatment.

Sequential Extraction of 239+240Pu and the Vertical Distribution of 239+240Pu, 137Cs, and Heavy Metals in Chang-Bai Mountains’ Grassland Soil

To establish a 239+240Pu, 137Cs, and heavy metal reference soil site in Northeast China, three grassland soil cores were collected from the Lao-Ye-Ling Mountain, which is a branch of the Chang-Bai Mountains. The activities were in the range of 0.041–2.752 mBq/g for 239+240Pu and in the range of 0.2–57.6 mBq/g for 137Cs. The 240Pu/239Pu atomic ratios were 0.161–0.186, showing that 239+240Pu in the study area originated from the global fallout. Also, 239+240Pu, 137Cs, and excess 210Pb were enriched in the surface soil. The convective–dispersion equation model provided the lower apparent dispersion coefficients (D) and apparent convection velocities (v) for both 239+240Pu and 137Cs. The soil erosion rate in this study area was estimated by an erosion model, which was lower than that in the other area of Northeast China. 239+240Pu in the different soil fractions was analyzed by a sequential extraction method, and the result showed that 239+240Pu was mainly adsorbed by Fe/Mn oxides and their associated organic matter (NOMFe/Mn-oxides fraction). Except for Fe, all other heavy metals from the anthropogenic source were enriched in the surface soil. The pollution level of heavy metals in this study area was lower. In general, the alpine grassland soil of the Lao-Ye-Ling Mountain can be used as a reference soil site to study environmental pollution and soil erosion and provided some reference baselines for future multidisciplinary studies in Northeast Asia.

On how non-facetted crystals affect crystallization processes

In crystallization processes, suspensions are agitated in order to equilibrate concentration and temperature gradients. Crystal/stirrer, crystal/crystal and/or crystal/wall collisions lead to abrasion and secondary nucleation and hence to non-facetted crystals. While abrasion and growth are studied quite well individually in the literature, their interaction is not well understood. In addition, crystals are usually assumed to be facetted. We hypothesize that this assumption is not valid when damaged crystals grow. Therefore, in this contribution, we aim at understanding the interaction of crystal growth and abrasion on process scale under consideration of non-facetted crystals. We use recently developed and experimentally validated models for growth and abrasion simulations of abraded crystals on a single crystal scale, to derive suitable advection rates for a three dimensional population balance model (PBM). On the process scale, the PBM then considers the effects of growth and abrasion on crystal shape and vice versa. PBM simulations show that non-ideal shape increases the overall volume growth rate not only through an increase in overall surface area but also because it yields fast growing surface. We discuss our results in context of how neglecting shape may lead to misinterpretation of experimental data. For this purpose we explain that our approach explains apparent growth rate dispersion through non-facetted crystal shapes.

Mineralization Based on CSAMT and SIP Sounding Data: A Case Study on the Hadamengou Gold Deposit in Inner Mongolia

The Hadamengou deposit is the largest gold deposit in Inner Mongolia. However, given that the sources of ore-forming alkaline magmatic hydrothermal solutions and ore-controlling structures are still controversial, the theories behind the genesis of the deposit have been controversial. In this study, four controlled-source audio magnetotellurics (CSAMT) and spectral induced polarization (SIP) profiles in the mining area were used to obtain the underground resistivity model and the pseudo section map of the apparent frequency dispersivity based on fine inversion. In the resistivity model, there are two high-resistivity blocks with resistivity greater than 3000 Ω m and three low-resistivity channels with resistivity less than 50 Ω m. Combined with the regional geological and drilling data, it is inferred that the high-resistance bodies, R4 and R5, may be alkaline magmatic intrusions related to multiple stages of magmatic hydrothermal activities, ranging from the Precambrian to Yanshanian periods. The highly conductive channels, C3, C5, and C4, may represent the Baotou-Hohhot fault, secondary faults, and ductile shear zone, respectively, which were formed in the Precambrian era and underwent multiple activations during the Hercynian to Yanshanian period. According to the spatial relationship, it is inferred that the ductile shear zone is an important ore-controlling and ore-hosting structure. However, the Baotou–Hohhot fault may be a pre-metallogenic fault rather than an ore-controlling fault. By comparing the resistivity model with the pseudo section of the apparent frequency dispersivity, it was found that all the known gold veins are located in the superimposed area of low resistivity and high-frequency dispersivity. It is speculated that the ductile shear zone outside the alkaline magmatic rock with the superimposed characteristics of low resistivity and high-frequency dispersivity is the favorable area for mineralization.

Synthetic relaxometry combined with MUSE DWI and 3D-pCASL improves detection of hippocampal sclerosis

PurposeTo investigate the diagnostic value of synthetic MRI combined MUSE DWI and 3D-pCASL in hippocampal sclerosis (HS). MethodA total of 30 HS patients participated in the study. At the same time, 51 healthy volunteers were collected as the control group. All patients and healthy volunteers underwent epilepsy MR scanning protocol (including oblique coronal MAGiC, MUSE DWI, and axial 3D-pCASL) at 3.0 T MR scanner.The independent samples T test and Mann-Whitney U test were used to compare the differences of the apparent dispersion coefficient(ADC), cerebral blood flow(CBF) and quantitative parameters, including T1 relaxation time (T1), T2 relaxation time (T2), and proton density (PD) values, in the hippocampus of the affected side of HS and the contralateral and control groups, respectively. The diagnostic performance was evaluated using binary logistic regression analysis and area under the receiver operating characteristic (ROC) curves (AUC). ResultsSignificant statistical differences in T1, T2, CBF, and ADC values were observed between the affected hippocampus of HS patients and contralateral and control hippocampus (all P < 0.005). The T2 has higher discrimination abilities compared with other univariable parameters, with the AUC of 0.899. The combined T2, ADC and CBF model had the best diagnostic performance of HS in MTLE patients with AUC, sensitivity and specificity of 0.946, 86.67 %, 93.33 %, respectively. ConclusionsRelaxometry parameters derived from synthetic MRI contributed to diagnosis of HS. The proposed approach combining T2, ADC and CBF showed a strong diagnostic capability.