Effective Bidirectional Mott-Schottky Catalysts Derived from Spent LiFePO4 Cathodes for Robust Lithium-Sulfur Batteries.

It is deemed as a tough yet profound project to comprehensively cope with a range of detrimental problems of lithium-sulfur batteries (LSBs), mainly pertaining to the shuttle effect of lithium polysulfides (LiPSs) and sluggish sulfur conversion. Herein, a Co2P-Fe2P@N-doped carbon (Co2P-Fe2P@NC) Mott-Schottky catalyst is introduced to enable bidirectionally stimulated sulfur conversion. This catalyst is prepared by simple carbothermal reduction of spent LiFePO4 cathode and LiCoO2. The experimental and theoretical calculation results indicate that thanks to unique surface/interface properties derived from the Mott-Schottky effect, full anchoring of LiPSs, mediated Li2S nucleation/dissolution, and bidirectionally expedited "solid⇌liquid⇌solid" kinetics can be harvested. Consequently, the S/Co2P-Fe2P@NC manifests high reversible capacity (1569.9 mAh g-1), superb rate response (808.9 mAh g-1 at 3C), and stable cycling (a low decay rate of 0.06% within 600 cycles at 3C). Moreover, desirable capacity (5.35 mAh cm-2) and cycle stability are still available under high sulfur loadings (4-5 mg cm-2) and lean electrolyte (8 µL mg-1) conditions. Furthermore, the as-proposed universal synthetic route can be extended to the preparation of other catalysts such as Mn2P-Fe2P@NC from spent LiFePO4 and MnO2. This work unlocks the potential of carbothermal reduction phosphating to synthesize bidirectional catalysts for robust LSBs.

Ultralow-level all-optical self-switching in a nanostructured moiré superlattice.

We report an all-optical self-switching performed at an ultralow-level of intensity in a nanostructured moiré superlattice on a silicon platform. The moiré superlattice was formed by twisting two sets of triangular lattices in a silicon membrane in the same layer with a twist angle of 9.43°. The near flatband was formed, and the electric field was well confined in the center of the superlattice, which enabled all-optical switching under an ultralow intensity when the Kerr nonlinearity of silicon was considered. The intensity, which was reduced to 300 W/m2 and even 20 W/m2, can cause the transmittance of the nanostructure to change from 0 to 80% under x- and y-polarized pump light, respectively, and could be further decreased by optimizing the nanostructure or nonlinear materials. The results indicate that moiré superlattices fabricated from nonlinear materials are promising for integrated all-optical devices.

Performance of 2D BLADE turbo gradient- and spin-echo diffusion-weighted imaging in the quantitative diagnosis of recurrent temporal bone cholesteatoma.

BACKGROUND: Diffusion-weighted imaging (DWI) has become an important tool for the detection of cholesteatoma. The purpose of this study was to explore the value of 2D BLADE turbo gradient- and spin-echo imaging (TGSE BLADE) DWI in the quantitative diagnosis of recurrent temporal bone cholesteatoma (CS). METHODS: From March 2018 to October 2021, 67 patients with suspected recurrence of temporal bone CS after assessment by clinical otorhinolaryngologists who had undergone previous ear surgery for CS were prospectively evaluated by magnetic resonance imaging (MRI). Two radiologist assessed images independently. Quantitative parameters such as signal intensity ratio (SIR) calculated using, as a reference, the inferior temporal cortex (SIRT) and the background noise (SIRN), apparent diffusion coefficient (ADC) value, and ADC ratio (with pons as reference) measured on TGSE BLADE sequences were assessed. Using receiver operating characteristic (ROC) curve analysis, the optimal threshold and diagnostic performance for diagnosing recurrent CS were determined. Pair-wise comparison of the ROC curves was performed using the area under the ROC curve (AUC). RESULTS: Finally, 44 patients were included in this study, including 25 CS and 19 non-cholesteatoma (NCS). Mean SIRT and mean SIRN on TGSE BLADE DWI were significantly higher for CS than NCS lesions (p < 0.001). Meanwhile, mean ADC values and mean ADC ratios on ADC maps were significantly lower in the CS group than in the NCS group (p < 0.001). According to ROC analysis, the diagnostic efficacy of quantitative parameters such as SIRT (AUC = 0.967), SIRN (AUC = 0.979), ADC value (AUC = 1.0), and ADC ratio (AUC = 0.983) was significantly better than that of qualitative DWI (AUC = 0.867; p = 0.007, 0.009, 0.011 and 0.037, respectively). CONCLUSIONS: Residual/recurrent temporal bone CS can be accurately detected using quantitative evaluation of TGSE BLADE DWI.

BLADE turbo gradient- and spin-echo in the assessment of sinonasal lesions: a comprehensive comparison of image quality in readout-segmented echo-planar imaging.

BACKGROUND: A two-dimensional turbo gradient-echo and spin-echo diffusion-weighted pulse sequence with a non-Cartesian BLADE trajectory (TGSE BLADE) can eliminate image artifacts and distortion with clinically acceptable scan times. This process has the potential to overcome the shortcomings of current diffusion-weighted imaging (DWI) techniques, especially in the sinonasal region. PURPOSE: To investigate the feasibility of TGSE BLADE in the assessment of sinonasal lesions and compare the quality of TGSE BLADE with RESOLVE images both qualitatively and quantitatively. MATERIAL AND METHODS: A total of 36 patients with sinonasal lesions were included in this prospective study. DW images acquired using TGSE BLADE and RESOLVE were performed with the same acquisition time. Two independent observers evaluated the qualitative parameters (overall image quality, lesion visibility, and geometric distortion) and quantitative parameters (geometric distortion ratio [GDR], signal-to-noise ratio [SNR], contrast, contrast-to-noise ratio [CNR], and apparent diffusion coefficient [ADC] value) of the two sequences. RESULTS: Qualitative assessment revealed that TGSE BLADE exhibited higher overall image quality (P < 0.001) and lesion visibility (P < 0.001) and less geometric distortion (P < 0.001) than RESOLVE. Quantitative assessment showed that TGSE BLADE images exhibited higher contrast (P < 0.001) and CNR (P < 0.001) and lower GDR (P < 0.05) and SNR (P < 0.001) than RESOLVE images. The ADC value of TGSE BLADE was significantly lower than that of RESOLVE (P < 0.05). CONCLUSION: TGSE BLADE can reduce susceptibility artifacts and geometric distortion more than RESOLVE and appears to be a promising diffusion imaging sequence for the assessment of sinonasal lesions.

Detection of cholesteatoma: 2D BLADE turbo gradient- and spin-echo imaging versus readout-segmented echo-planar diffusion-weighted imaging.

PURPOSE: This study is to compare the accuracy of 2D BLADE turbo gradient- and spin-echo imaging (TGSE BLADE) diffusion-weighted imaging (DWI) with that of readout-segmented echo-planar (RESOLVE) DWI in the detection of primary and residual/recurrent temporal bone cholesteatoma. METHODS: The prospective study population consisted of 58 patients who were underwent magnetic resonance (MR) imaging for the evaluation of suspected temporal bone cholesteatoma. Two radiologists independently evaluated the two sequences. Kappa (k) statistics, the intra-class correlation coefficient (ICC), and a paired t test were used for statistical analysis. RESULTS: Of the 58 patients included, all had histo-pathologically confirmed cholesteatomas. In ≤ 3 mm group (n = 13), TGSE BLADE sequence correctly identified all cases except one that was recorded as equivocal on both sequences because of high signal intensity on T1WI; while on RESOLVE sequences, 6 were positive, 4 were equivocal, and 3 were false negative. For > 3 mm group (n = 45), detection performance was similar between the two sequences. The mean ADC of cholesteatoma on TGSE BLADE DWI was 0.923 × 10-3 mm2/s, and the mean ADC of cholesteatoma on RESOLVE DWI was 0.949 × 10-3 mm2/s, with no significant difference in the mean ADC values of cholesteatoma measured on the two sequences (p = 0.9216). CONCLUSION: TGSE BLADE outperforms RESOLVE in the detection of small temporal bone cholesteatoma ≤ 3 mm.

Frequent ploidy changes in Salicaceae indicates widespread sharing of the salicoid whole genome duplication by the relatives of Populus L. and Salix L.

BACKGROUNDS: Populus and Salix belong to Salicaceae and are used as models to investigate woody plant physiology. The variation of karyotype and nuclear DNA content can partly reflect the evolutionary history of the whole genome, and can provide critical information for understanding, predicting, and potentially ameliorating the woody plant traits. Therefore, it is essential to study the chromosome number (CN) and genome size in detail to provide information for revealing the evolutionary process of Salicaceae. RESULTS: In this study, we report the somatic CNs of seventeen species from eight genera in Salicaceae. Of these, CNs for twelve species and for five genera are reported for the first time. Among the three subfamilies of Salicaceae, the available data indicate CN in Samydoideae is n = 21, 22, 42. The only two genera, Dianyuea and Scyphostegia, in Scyphostegioideae respectively have n = 9 and 18. In Salicoideae, Populus, Salix and five genera closely related to them (Bennettiodendron, Idesia, Carrierea, Poliothyrsis, Itoa) are based on relatively high CNs from n = 19, 20, 21, 22 to n = 95 in Salix. However, the other genera of Salicoideae are mainly based on relatively low CNs of n = 9, 10, 11. The genome sizes of 35 taxa belonging to 14 genera of Salicaceae were estimated. Of these, the genome sizes of 12 genera and all taxa except Populus euphratica are first reported. Except for Dianyuea, Idesia and Bennettiodendron, all examined species have relatively small genome sizes of less than 1 pg, although polyploidization exists. CONCLUSIONS: The variation of CN and genome size across Salicaceae indicates frequent ploidy changes and a widespread sharing of the salicoid whole genome duplication (WGD) by the relatives of Populus and Salix. The shrinkage of genome size after WGD indicates massive loss of genomic components. The phylogenetic asymmetry in clade of Populus, Salix, and their close relatives suggests that there is a lag-time for the subsequent radiations after the salicoid WGD event. Our results provide useful data for studying the evolutionary events of Salicaceae.

Ultimate conversion efficiency of second harmonic generation in all-dielectric resonators of quasi-BICs in consideration of nonlinear refraction of dielectrics.

We investigate second harmonic generation (SHG) in all-dielectric resonance nanostructures of high-Q factors assisted by quasi-bound states in the continuum (quasi-BICs). The typical resonators, e.g., guided-mode resonance gratings and asymmetric metasurfaces, fabricated by AlGaAs were numerically studied with the consideration of nonlinear refraction of AlGaAs. The resonance peak and line-shape of linear transmission and SHG spectra in the resonators can be dramatically changed under intense pump intensities. The SHG conversion efficiency in the nanostructures working at quasi-BICs is much lower than the traditionally expected values without considering the nonlinear refraction of dielectrics. The ultimate SHG conversion efficiency is finally obtained. The investigation has the significance for the design and understanding of efficient nonlinear metasurfaces of high-Q factors.

Clinical value of high-resolution dynamic contrast-enhanced (DCE) MRI in diagnosis of cutaneous squamous cell carcinoma.

BACKGROUND: While uncomplicated cases of skin squamous cell carcinoma (cSCC) can be treated with surgery topical therapy alone, more objective and non-invasive examination methods are needed to guide clinicians to make more detailed biopsy and surgical plans for lesions with atypical or subcutaneous growth. High-resolution magnetic resonance imaging (HR-MRI) is a novel skin imaging method. MATERIALS AND METHODS: Prospective collection of 19 patients with clinically suspected cSCC. All patients underwent high-resolution DCE-MRI using a 70-mm microscopy coil before operation. The imaging features and results of surgical pathology were recorded. Ktrans , Kep , Ve values, and the time-signal curve (TIC) types were determined using DCE images. RESULTS: 16 cases of cSCC, 3 cases of acanthoma. The subcutaneous invasion of all lesions was clearly displayed, of which 8 lesions invaded the subcutaneous fat layer, 5 invaded the muscle layer, 1 invaded the periosteum, 2 invaded the cap fascia, and the layer of all lesions invasion judged by HR-MR imaging was consistent with the postoperative pathology. The main manifestations of cSCC were ill-defined margin, obvious inhomogeneous enhancement, higher perfusion parameters value and type-III TIC, while acanthoma showed well-defined and type-I TIC. Some imaging findings (such as boundary, enhancement) and DCE perfusion parameters of the two groups overlap. CONCLUSION: High-resolution DCE-MRI can fully and directly display the subcutaneous invasion of cSCC, and more work needs to be done to prove its value. Next, we will expand the sample size, and further explore its value in the differential diagnosis and prognosis evaluation of cSCC from acanthoma or other skin tumors.

Association Between Small Vessel Disease Markers, Medial Temporal Lobe Atrophy and Cognitive Impairment After Stroke: A Systematic Review and Meta-Analysis.

OBJECTIVES: Two-thirds of stroke survivors suffer from cognitive impairment, and up to one-third of them progress to dementia. However, the underlying pathogenesis is complex and controversial. Recent evidence has found that cerebral small vessel disease (SVD) markers and the Alzheimer's disease (AD) neuroimaging marker medial temporal lobe atrophy (MTLA), alone or in combination, contribute to the pathogenesis of poststroke cognitive impairment (PSCI). In the present systematic review and meta-analysis, we synthesized proof for these neuroimaging risk factors among stroke patients. MATERIALS AND METHODS: PUBMED, MEDLINE, EMBASE and the Cochrane Library were searched for studies investigating imaging predictors of cognitive impairment or dementia following stroke. Meta-analysis was conducted to compute the odds ratios (ORs). RESULTS: Thirteen studies were enrolled in the present study, and only ten of them, comprising 2713 stroke patients, were eligible for inclusion in the meta-analysis. MTLA was significantly correlated with PSCI (OR = 1.97, 95% CI: 1.48-2.62, I2 = 0.0%). In addition, white matter hyperintensities (WMH), as a neuroimaging marker of SVD, were associated with PSCI (OR = 1.17, 95% CI: 1.12-1.22, I2 = 0.0%). However, the presence of lacunar infarcts and enlarged perivascular spaces (EPVS) were not associated with the risk of PSCI. CONCLUSIONS: The findings of the present study suggest that MTLA and WMH were associated with an increased risk of PSCI.

Whole-tumor histogram analysis of monoexponential and advanced diffusion-weighted imaging for sinonasal malignant tumors: Correlations with histopathologic features.

BACKGROUND: The histopathological basis of monoexponential diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) in the characterization of sinonasal malignant tumors is still unclear. PURPOSE: To explore the correlations of histogram metrics from monoexponential DWI, IVIM, and DKI with histopathologic features in sinonasal malignant tumors. STUDY TYPE: Retrospective. SUBJECTS: In all, 76 patients with sinonasal malignant tumors. FIELD STRENGTH/SEQUENCE: Fourteen different b values (b = 0, 50, 100, 150, 200, 250, 300, 350, 400, 800, 1000, 1500, 2000, and 2500 sec/mm2 ) were used to perform different DWI models at 3.0T. ASSESSMENT: The whole-tumor histogram metrics were calculated on the apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (f), diffusion kurtosis (K), and diffusion coefficient (Dk) maps. Histopathologic features, including nuclear, cytoplasmic, cellular, stromal fractions, and the nuclear-to-cytoplasmic (N/C) ratio, were measured. STATISTICAL TESTS: Spearman correlations and stepwise multiple linear regression analyses were performed to determine the correlations between histogram metrics and histopathologic features. RESULTS: ADC, Dk, and f histogram metrics showed significant correlations with investigated histopathologic features; D and K histogram metrics were significantly correlated with cellular, stromal, and nuclear fractions (all P < 0.05). Significant correlations between the 75th percentile of D and cytoplasmic fraction and between the kurtosis of K and the N/C ratio were observed (P < 0.05). The skewness of Dk, K, and the 75th percentile of D were independently associated with cellular and nuclear fractions; the skewness of Dk and K were independently associated with stromal fraction (P < 0.05). DATA CONCLUSION: Monoexponential and advanced DWI histogram parameters were significantly correlated with histopathologic features in sinonasal malignancies. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:273-285.

A direct comparison of 3 T contrast-enhanced whole-heart coronary cardiovascular magnetic resonance angiography to dual-source computed tomography angiography for detection of coronary artery stenosis: a single-center experience.

BACKGROUND: In recent years, substantial advances have been made in noninvasive cardiac imaging, including cardiac computed tomography (CT) and cardiovascular magnetic resonance (CMR). The purpose of this study was to prospectively compare the diagnostic performance of contrast-enhanced whole heart coronary CMR angiography (CCMRA) to dual-source coronary CT angiography (CCTA) for the diagnosis of significant coronary stenoses (≥50%) in patients with known or suspected coronary artery disease (CAD) referred for conventional x-ray coronary angiography. METHODS: Our objective was to directly compare the diagnostic accuracy of contrast-enhanced whole-heart CCMRA (CE-CCMRA) to dual-source CCTA (DS-CCTA) for the detection of CAD. We prospectively studied 57 symptomatic patients with suspected or known CAD who were scheduled for conventional x-ray coronary angiography. Significant CAD was defined as an x-ray defined diameter reduction of ≥50% in a coronary artery with a reference diameter of ≥1.5 mm. RESULTS: CE-CCMRA and DS-CCTA were completed in 51 (89%) of 57 patients without complications. The acquisition times of CE-CCMRA and DS-CCTA, respectively, were 9.5 ± 3.1 min and 8.3 ± 1.4 s. On patient-based analysis, the sensitivity, specificity, positive and negative predictive value of CE-CCMRA and DS-CCTA were 93.5% versus 93.5%(P > 0.05), 85% versus 90%(P > 0.05), 90.6% versus 93.5%(P > 0.05), and 89.4% versus 90%(P > 0.05), respectively. The area under the curve (AUC) was 0.89 (95% CI: 0.79 to 0.99) for CE-CCMRA and 0.92 (95% CI: 0.83 to 1.00) for DS-CCTA. CONCLUSIONS: DS-CCTA was found to be superior to CE-CCMRA in the diagnosis of significant coronary stenoses (≥50%) in patients with suspected or known CAD scheduled for conventional x-ray coronary angiography, owing to shorter scanning times and higher spatial resolution. However, CE-CCMRA and DS-CCTA have similar diagnostic accuracies.

Performance of TGSE BLADE DWI compared with RESOLVE DWI in the diagnosis of cholesteatoma.

BACKGROUND: Based on its high resolution in soft tissue, MRI, especially diffusion-weighted imaging (DWI), is increasingly important in the evaluation of cholesteatoma. The purpose of this study was to evaluate the role of the 2D turbo gradient- and spin-echo (TGSE) diffusion-weighted (DW) pulse sequence with the BLADE trajectory technique in the diagnosis of cholesteatoma at 3 T and to qualitatively and quantitatively compare image quality between the TGSE BLADE and RESOLVE methods. METHOD: A total of 42 patients (23 males, 19 females; age range, 7-65 years; mean, 40.1 years) with surgically confirmed cholesteatoma in the middle ear were enrolled in this study. All patients underwent DWI (both a prototype TGSE BLADE DWI sequence and the RESOLVE DWI sequence) using a 3-T scanner with a 64-channel brain coil. Qualitative imaging parameters (imaging sharpness, geometric distortion, ghosting artifacts, and overall imaging quality) and quantitative imaging parameters (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR], contrast, and contrast-to-noise ratio [CNR]) were assessed for the two diffusion acquisition techniques by two independent radiologists. RESULT: A comparison of qualitative scores indicated that TGSE BLADE DWI produced less geometric distortion, fewer ghosting artifacts (P < 0.001) and higher image quality (P < 0.001) than were observed for RESOLVE DWI. A comparison of the evaluated quantitative image parameters between TGSE and RESOLVE showed that TGSE BLADE DWI produced a significantly lower SNR (P < 0.001) and higher parameter values (both contrast and CNR (P < 0.001)) than were found for RESOLVE DWI. The ADC (P < 0.001) was significantly lower for TGSE BLADE DWI (0.763 × 10- 3 mm2/s) than RESOLVE DWI (0.928 × 10- 3 mm2/s). CONCLUSION: Compared with RESOLVE DWI, TGSE BLADE DWI significantly improved the image quality of cholesteatoma by reducing magnetic sensitive artifacts, distortion, and blurring. TGSE BLADE DWI is more valuable than RESOLVE DWI for the diagnosis of small-sized (2 mm) cholesteatoma lesions. However, TGSE BLADE DWI also has some disadvantages: the whole image intensity is slightly low, so that the anatomical details of the air-bone interface are not shown well, and this shortcoming should be improved in the future.

Self-adapting multi-peak water-fat reconstruction for the removal of lipid artifacts in chemical exchange saturation transfer (CEST) imaging.

PURPOSE: Artifacts caused by strong lipid signals pose challenges in body chemical exchange saturation transfer (CEST) imaging. This study aimed to develop an accurate water-fat reconstruction method based on the multi-echo Dixon technique to remove lipid artifacts in CEST imaging. THEORY AND METHODS: It is well known that fat has multiple spectral peaks. Furthermore, RF pulses in CEST preparation saturate each fat peak at different levels, complicating fat modeling. Therefore, a self-adapting multi-peak model (SMPM) is proposed to update relative amplitudes of fat peaks using numerical calculation. With the SMPM-based updating, nonlinear least-squares fitting combined with IDEAL (Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation) algorithms was used for water-fat reconstruction and B0 mapping. The proposed method was compared with the reported 3-point Dixon method and the fixed multi-peak model in a phantom study using a fat-free Z-spectrum obtained from MR spectroscopy acquisition as the ground truth. This method was also validated by in vivo experiments on human breast. RESULTS: In the phantom experiments, the Z-spectrum from the SMPM-based method agreed well with the fat-free Z-spectrum from CEST-PRESS (point-resolved spectroscopy), validating the effective removal of lipid artifacts, while a decrease or a rise that appeared at -3.5 ppm was observed in the Z-spectrum from the 3-point method and the FMPM-based method, respectively. In the in vivo experiments, no lipid artifacts were observed in the Z-spectrum or the amide CEST map from the SMPM-based method in the fibro-glandular region of the breast with high fat fractions. CONCLUSION: The SMPM-based method successfully removes lipid artifacts and significantly improves the accuracy of CEST contrast.

Standard diffusion-weighted, diffusion kurtosis and intravoxel incoherent motion MR imaging of sinonasal malignancies: correlations with Ki-67 proliferation status.

OBJECTIVES: To explore the correlations of parameters derived from standard diffusion-weighted imaging (DWI), diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) with the Ki-67 proliferation status. METHODS: Seventy-five patients with histologically proven sinonasal malignancies who underwent standard DWI, DKI and IVIM were retrospectively reviewed. The mean, minimum, maximum and whole standard DWI [apparent diffusion coefficient (ADC)], DKI [diffusion kurtosis (K) and diffusion coefficient (Dk)] and IVIM [pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f)] parameters were measured and correlated with the Ki-67 labelling index (LI). The Ki-67 LI was categorised as high (> 50%) or low (≤ 50%). RESULTS: The K and f values were positively correlated with the Ki-67 LI (rho = 0.295~0.532), whereas the ADC, Dk and D values were negatively correlated with the Ki-67 LI (rho = -0.443~-0.277). The ADC, Dk and D values were lower, whereas the K value was higher in sinonasal malignancies with a high Ki-67 LI than in those in a low Ki-67 LI (all p < 0.05). A higher maximum K value (Kmax > 0.977) independently predicted a high Ki-67 status [odds ratio (OR) = 7.614; 95% confidence interval (CI) = 2.197-38.674; p = 0.017]. CONCLUSION: ADC, Dk, K, D and f are correlated with Ki-67 LI. Kmax is the strongest independent factor for predicting Ki-67 status. KEY POINTS: • DWI-derived parameters from different models are capable of providing different pathophysiological information. • DWI, DKI and IVIM parameters are associated with Ki-67 proliferation status. • K max derived from DKI is the strongest independent factor for the prediction of Ki-67 proliferation status.

Differentiating Neuromyelitis Optica-Related and Multiple Sclerosis-Related Acute Optic Neuritis Using Conventional Magnetic Resonance Imaging Combined With Readout-Segmented Echo-Planar Diffusion-Weighted Imaging.

PURPOSE: In clinical practice, acute optic neuritis (ON) associated with the development of neuromyelitis optica (NMO) after the first attack is often indistinguishable from that associated with multiple sclerosis (MS). We aimed to determine the optimal combination of features derived from conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging using readout-segmented echo-planar imaging (RESOLVE-DWI) for the differentiation of these conditions. MATERIALS AND METHODS: Orbital conventional MRI and RESOLVE-DWI were performed using a 3.0-T scanner on 54 patients with acute ON (26 NMO-related and 28 MS-related). The features detected by conventional MRI (including laterality, the enhancement pattern, and the extent and position of involvement) and the apparent diffusion coefficient (ADC) measurements were retrospectively compared between the NMO-related and MS-related groups. A multivariate logistic regression analysis was used to identify the most significant variables, and receiver operating characteristic curve analyses were performed to determine the ability of a combined diagnostic model based on the qualitative and quantitative characteristics identified in this study to differentiate the 2 conditions. RESULTS: The multivariate logistic regression analyses indicated that the presence of chiasm involvement and lower ADC values were significantly associated with NMO-related acute ON compared with MS-related acute ON (P = 0.037 and 0.008, respectively). The diagnostic criterion of chiasm involvement or "ADC < 791 × 10 mm/s and chiasm involvement" had the highest specificity (96.9%), and "ADC < 791 × 10 mm/s or chiasm involvement" showed the optimal sensitivity (77.8%) for differentiating NMO-related from MS-related acute ON. CONCLUSIONS: Conventional MRI RESOLVE-DWI is helpful for differentiating NMO-related acute ON from MS-related acute ON. The combination of the ADC value chiasm involvement appears to be effective for discriminating these 2 types of acute ON.

Are ADC values of readout-segmented echo-planar diffusion-weighted imaging (RESOLVE) correlated with pathological prognostic factors in rectal adenocarcinoma?

BACKGROUND: Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values as imaging biomarkers of rectal cancer are currently a hot research spot. The use of ADC values for preoperative judgment of pathological features in rectal cancer has been generally accepted. The image quality evaluation of conventional diffusion is severe deformation, and the measurement of ADC values can easily lead to bias. Readout-segmented echo-planar diffusion-weighted imaging (RESOLVE) provides high signal-to-noise ratio images and significantly reduces distortions caused by magnetosensitive effects. The purpose of this study was to explore the correlations between ADC values of RESOLVE and pathological prognostic factors in rectal adenocarcinoma. METHODS: We collected pathological data of 89 patients with pathologically confirmed rectal adenocarcinoma who directly underwent surgical resection without receiving adjuvant therapy. The patients were grouped according to the pathologic type, gross classification, degree of differentiation, TN stage, and immunohistochemical expression of epidermal growth factor receptor (EGFR). RESULTS: RESOLVE ADC values of rectal cancer were measured at b = 800, and correlations between the RESOLVE ADC values obtained in different groups were analysed. We found that RESOLVE ADC values in the ulcer-type group were significantly higher than those in the eminence-type group. CONCLUSION: RESOLVE ADC values in different pathologic types of rectal cancer were significantly different. RESOLVE ADC values in the EGFR-positive group were significantly lower than those in the EGFR-negative group. There was no significant difference in RESOLVE ADC values between different degrees of pathologic differentiation, TN stages, and positive or negative lymph nodes. The quantitative description of RESOLVE ADC values could be used to assess the biological behaviour of rectal adenocarcinoma.

Radar HRRP Target Recognition Based on Stacked Autoencoder and Extreme Learning Machine.

A novel radar high-resolution range profile (HRRP) target recognition method based on a stacked autoencoder (SAE) and extreme learning machine (ELM) is presented in this paper. As a key component of deep structure, the SAE does not only learn features by making use of data, it also obtains feature expressions at different levels of data. However, with the deep structure, it is hard to achieve good generalization performance with a fast learning speed. ELM, as a new learning algorithm for single hidden layer feedforward neural networks (SLFNs), has attracted great interest from various fields for its fast learning speed and good generalization performance. However, ELM needs more hidden nodes than conventional tuning-based learning algorithms due to the random set of input weights and hidden biases. In addition, the existing ELM methods cannot utilize the class information of targets well. To solve this problem, a regularized ELM method based on the class information of the target is proposed. In this paper, SAE and the regularized ELM are combined to make full use of their advantages and make up for each of their shortcomings. The effectiveness of the proposed method is demonstrated by experiments with measured radar HRRP data. The experimental results show that the proposed method can achieve good performance in the two aspects of real-time and accuracy, especially when only a few training samples are available.

Nitrogen addition exerts a stronger effect than elevated temperature on soil available nitrogen and relation to soil microbial properties in the rhizosphere of Camellia sinensis L. seedlings.

As the global climate changes, elevated atmospheric temperature and nitrogen (N) deposition co-occur in natural ecosystems, which affects rhizosphere soil nutrient by altering allocation of roots and its availability to soil microorganism. Elevated temperature in combination with N deposition is expected to affect soil available N and its relation to microbial properties, but this issue has not been extensively examined. Here, we investigated soil available N and its relation to microbial properties in rhizosphere of Camellia sinensis L. seedlings exposed to elevated temperature using a passive warming device in combination with N-added soil. Elevated temperature did not significantly affect soil pH, total organic carbon (TOC), total nitrogen (TN), the ratio of carbon and nitrogen (C:N ratio), total phosphorus (TP), available N ((N in ammonium (NH4+-N) and N in nitrate (NO3--N)) (NH4+-N + NO3--N)/TN, α-glucosidase (αG), ß-glucosidase (ßG), cellobiohydrolase (CBH), N-acetyl-glucosaminidase (NAG), and phenol oxidase (PPO) activities, while significantly stimulated root total length of tea seedlings (3.9%), root dry biomass (10.2%), soil microbial biomass carbon (MBC) (7.4%), microbial biomass nitrogen (MBN) (8.6%), and acid phosphatase (ACP) (8.8%). While N addition significantly (p < 0.05) stimulated root dry biomass of tea seedlings (14.1%), root total length (6.2%), root average diameter (6.7%), soil TN, available N, (NH4+-N + NO3--N)/TN, and MBN under elevated temperature. Soil aG, ßG, CBH, and ACP activity increase significantly (p < 0.05) under elevated temperature + N relative to elevated temperature alone. Generally, N addition led to increased available nitrogen and microbial properties in rhizosphere soil of tea seedlings exposed to elevated temperature by stimulating root properties, soil nitrogen, microbial biomass N, and enzyme activity. Redundancy analysis and Pearson correlation analysis suggested that N addition lead to higher correlation between soil available N and microbial properties exposed to elevated temperature. Our results indicated nitrogen addition exerts a stronger effect than elevated temperature on soil fertility and microbiological cycle in the rhizosphere of Camellia sinensis L. seedlings. The conclusion helps us understand the response mechanism of soil rhizosphere microenvironment to N deposition under global warming scenarios.

Histogram Analysis of Quantitative Susceptibility Mapping for the Diagnosis of Parkinson's Disease.

RATIONALE AND OBJECTIVES: To investigate the diagnostic performance of histogram analysis combined with quantitative susceptibility mapping (QSM) for differentiating Parkinson's disease (PD) patients from healthy controls. METHODS: We included 35 patients with PD diagnosed by two neurologists from August 2019 to January 2020 in our hospital in this prospective study. The clinical diagnosis was based on the Movement Disorder Society Clinical Diagnostic Criteria for PD. At the same time, 23 healthy volunteers matched for age and sex were recruited as controls. The Mini Mental State Examination, the third part of the Parkinson's Disease Rating Scale, the Hoehn & Yahr stages, and disease duration (year) were used to assess the PD patients. QSM was performed using a 3T MR scanner. The regions of interest were depicted according to the head of the caudate nucleus(CN), globus pallidus(GP), putamina (PUT), thalmus(TH), substantia nigra (SN), red nucleus(RN), and dentate nucleus. Then the corresponding histogram features were extracted. The Mann-Whitney U test was used to identify significant histogram features for differentiating PD patients from healthy controls. Area under the receiver operating characteristics curve (AUC) analysis was conducted to evaluate the diagnostic performance of all significant histogram features. Multivariate logistic regression analysis was performed to identify the best combined model for all seven nuclei. Differences among the AUCs were compared pairwise. RESULTS: Histogram features in all nuclei except TH showed significant differences between the groups. Among the single features, the 10th percentile of SN (SNP10) yielded the highest AUC of 0.894, with the highest specificity of 86.86% for differentiating PD patients from healthy controls. The 75th percentile of PUT (PUTP75) yielded the highest sensitivity of 97.14%. In the multivariate logistic regression analysis, SNP10 combined with PUTP75 yielded the highest diagnostic performance with the highest AUC of 0.911, the highest specificity of 91.30% and an excellent sensitivity of 92.40%. CONCLUSION: QSM combined with histogram analysis successfully distinguished PD patients from healthy controls, and the result was notably superior to the mean value.

Fractionation analysis and risk assessment of potential toxic elements in reservoir sediments in central China.

The pollution of potential toxic elements (PTEs) in the environment is a persistent issue and draws public attention constantly. However, there is no study comprehensively assessing the PTE pollution of water supply reservoirs in central China. This study determined the total contents and fractions of seven PTEs in 10 water supply reservoirs of central China, and evaluated PTE pollution risks by adopting various models. The results indicated that PTE pollution in water supply reservoirs was lower comparing that in estuary or river sediments, and Mn (manganese) was the predominant PTE in central China reservoirs. Fractionation analysis revealed that for B1 fraction (exchangeable/acid-soluble fraction) of Mn, Zn (zinc) and B2 fraction (reducible fraction) of Pb (lead) was high, while the effective state portion of Cr (chromium) was small. The monomial potential ecological risk indices and Igeo values were low among most samples, indicating overall modest PTE pollution. However, the results of the individual contamination factor (ICF) suggested that Pb might lead to potential health risks to human beings.