Imaging Mapping Research Articles

Biocompatibility of Water-Dispersible Pristine Graphene and Graphene Oxide Using a Close-to-Human Animal Model: APilot Study on Swine.

Graphene-based materials (GBMs) are of considerable interest for biomedical applications, and the pilot study on the toxicological and immunological impact of pristine graphene (GR) and graphene oxide (GO) using swine as a close-to-human provides valuable insights. First, ex vivo experiments are conducted on swine blood cells, then GBMs are injected intraperitoneally (i.p.) into swine. Hematological and biochemical analyses at various intervals indicate that neither GO nor GR cause systemic inflammation, pro-coagulant responses, or renal or hepatic dysfunction. Importantly, no systemic toxicity is observed. Analysis of a panel of 84 immune-related genes shows minimal impact of GO and GR. The animals are sacrificed 21 days post-injection, and transient absorption imaging and Raman mapping show the presence of GO and GR in the mesentery only. Histological evaluation reveals no signs of alterations in other organs. Thus, clusters of both materials are detected in the mesentery, and GO aggregates are surrounded only by macrophages with the formation of granulomas. In contrast, modest local reactions are observed around the GR clusters. Overall, these results reveal that i.p. injection of GBMs resulted in a modest local tissue reaction without systemic toxicity. This study, performed in swine, provides essential guidance for future biomedical applications of graphene.

Characterizing myocardial edema and fibrosis in hypertensive crisis with cardiovascular magnetic resonance imaging.

A hypertensive crisis is associated with an increased risk of cardiovascular events. Although altered cardiac structure, function, and myocardial architecture on cardiovascular magnetic resonance (CMR) have been associated with increased adverse events in hypertensive patients, the studies did not include patients with hypertensive crisis. Our study aimed to determine myocardial tissue characteristics in patients with hypertensive crisis using CMR imaging. Participants underwent comprehensive CMR imaging at 1.5T. The imaging protocol included cine-, T2-weighted-, contrasted- and multi-parametric mapping images. Blood and imaging biomarkers were compared in hypertensive emergency and hypertensive urgency. Predictors of myocardial edema was assessed using linear regression. The predictive value of T1- and T2 mapping for identifying hypertensive emergency (from urgency) was assessed with receiver operator characteristics curves. Eighty-two patients (48.5 ± 13.4 years, 57% men) were included. Hypertensive emergency constituted 78%. Native T1 was higher in patients with LVH compared to those without (1056 ± 33 vs. 1013 ± 40, P < 0.001), and tended to be higher in hypertensive emergency than urgency (1051 ± 37 vs. 1033 ± 40, P = 0.077). T2-w signal intensity (SI) ratio and T2 mapping values were higher in hypertensive emergency (1.5 ± 0.2 vs. 1.4 ± 0.1, P = 0.044 and 48 ± 2 vs. 47 ± 2, P = 0.004), and in patients with than without LVH (1.5 ± 0.2 vs. 1.4 ± 0.1, P = 0.045 and P = 0.030). A trend for higher extracellular volume was noted in hypertensive emergency compared to urgency (25 ± 4 vs. 22 ± 3, P = 0.050). Native T1 correlated with T2 mapping (rs = 0.429, P < 0.001), indexed LV mass (rs = 0.493, P < 0.001), cardiac troponin (rs = 0.316, P < 0.001) and NT-proBNP (rs = 0.537, P < 0.001), while T2 correlated with cardiac troponin (rs = 0.390, P < 0.001), and NT-proBNP (rs = 0.348, P < 0.001). Non-ischemic LGE pattern occurred in 59% and was 21% more prevalent in the hypertensive emergency group (P = 0.005). Our findings demonstrate that hypertensive crisis is associated with distinct myocardial tissue alterations, including increased myocardial edema and fibrosis, as detected on CMR. Patients with hypertensive emergency had a higher degree of myocardial oedema than hypertensive urgency. Further research is necessary to explore the prognostic value of these findings.

Radiomic features on multiparametric MRI for differentiating pseudoprogression from recurrence in high-grade gliomas.

Distinguishing between tumor recurrence and pseudoprogression (PsP) in high-grade glioma postoperatively is challenging. This study aims to enhance this differentiation using a combination of intratumoral and peritumoral radiomics. To assess the effectiveness of intratumoral and peritumoral radiomics in improving the differentiation between high-grade glioma recurrence and pseudoprogression after surgery. A total of 109 cases were randomly divided into training and validation sets, with 1316 features extracted from intratumoral and peritumoral volumes of interest (VOIs) on conventional magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) maps. Feature selection was performed using the mRMR algorithm, resulting in intratumoral (100 features), peritumoral (100 features), and combined (200 features) subsets. Optimal features were then selected using PCC and RFE algorithms and modeled using LR, SVM, and LDA classifiers. Diagnostic performance was compared using area under the receiver operating characteristic curve (AUC), evaluated in the validation set. A nomogram was established using radscores from intratumoral, peritumoral, and combined models. The combined model, utilizing 14 optimal features (8 peritumoral, 6 intratumoral) and LR as the best classifier, outperformed the single intratumoral and peritumoral models. In the training set, the AUC values for the combined model, intratumoral model, and peritumoral model were 0.938, 0.921, and 0.847, respectively; in the validation set, the AUC values were 0.841, 0.755, and 0.705. The nomogram model demonstrated AUCs of 0.960 (training set) and 0.850 (validation set). The combination of intratumoral and peritumoral radiomics is effective in distinguishing high-grade glioma recurrence from pseudoprogression after surgery.

Myelin water imaging of in vivo and ex vivo human brains using multi-echo gradient echo at 3 T and 7 T.

To compare the myelin water fraction (MWF) measurements between 3 T and 7 T and between in vivo and ex vivo human brains, and to investigate the relationship between multi-echo gradient-echo (mGRE)-based 3D MWF and myelin content using histological staining, which has not been validated in the human brain. In this study, we performed 3D mGRE-based MWF measurements on five ex vivo human brain hemispheres and five healthy volunteers at 3 T and 7 T with 1 mm isotropic resolution. The data were fitted with the based on a three compartment complex-valued model to estimate MWF. We obtained myelin basic protein (MBP) staining from two tissue blocks and co-registered the MWF map and histology image for voxel-wise correlation between the two. The MWF values measured from 7 T were overall higher than 7 T, but data between the two field strength demonstrated high correlations both in vivo (r = 0.88) and ex vivo (r = 0.83) across 19 white matter regions. Moreover, the MWF measurements showed a good agreement between in vivo and ex vivo assessments at 3 T (r = 0.61) and 7 T (r = 0.54). Based on MBP staining, the MWF values exhibited strong positive correlations with myelin content on both 3 T (r = 0.68 and r = 0.78 for the two tissue blocks) and 7 T (r = 0.64 and r = 0.82 for the two tissue blocks). The findings demonstrated that the mGRE-based MWF mapping can be used to quantify myelin content in the human brain, despite the field-strength dependency of the measurements.

Retraction: Comparing the predictive value of quantitative magnetic resonance imaging parametric response mapping and conventional perfusion magnetic resonance imaging for clinical outcomes in patients with chronic ischemic stroke.

[This retracts the article DOI: 10.3389/fnins.2023.1177044.].

A phenological-knowledge-independent method for automatic paddy rice mapping with time series of polarimetric SAR images

Paddy rice, which sustains more than half of the global population, requires accurate and efficient mapping to ensure food security. Synthetic aperture radar (SAR) has become indispensable in this process due to its remarkable ability to operate effectively in adverse weather conditions and its sensitivity to paddy rice growth. Phenological-knowledge-based (PKB) methods have been commonly employed in conjunction with time series of SAR images for paddy rice mapping, primarily because they eliminate the need for training datasets. However, PKB methods possess inherent limitations, primarily stemming from their reliance on precise phenological information regarding paddy rice growth. This information varies across regions and paddy rice varieties, making it challenging to use PKB methods effectively on a large spatial scale, such as the national or global scale, where collecting comprehensive phenological data becomes impractical. Moreover, variations in farming practices and field conditions can lead to differences in paddy rice growth stages even within the same region. Using a generalized set of phenological knowledge in PKB methods may not be suitable for all paddy fields, potentially resulting in errors in paddy rice extraction. To address the challenges posed by PKB methods, this study proposed an innovative approach known as the phenological-knowledge-independent (PKI) method for mapping paddy rice using time series of Sentinel-1 SAR images. The central innovation of the PKI method lies in its capability to map paddy rice without relying on specific knowledge of paddy rice phenology or the need for a training dataset. This was made possible by the incorporation of three novel metrics: VH and VV normalized maximum temporal changes (NMTC) and VH temporal mean, derived from the distinctions between paddy rice and other land cover types in time series of SAR images. The PKI method was rigorously evaluated across three regions in China, each featuring different paddy rice varieties. Additionally, the PKI method was compared with two prevalent phenological-knowledge-based techniques: the automated paddy rice mapping method using SAR flooding signals (ARM-SARFS) and the manual interpretation of unsupervised clustering results (MI-UCR). The PKI method achieved an average overall accuracy of 97.99%, surpassing the ARM-SARFS, which recorded an accuracy of 89.65% due to errors stemming from phenological disparities among different paddy fields. Furthermore, the PKI method delivered results on par with the MI-UCR, which relied on the fusion of SAR and optical image time series, achieving an accuracy of 97.71%. As demonstrated by these findings, the PKI method proves highly effective in mapping paddy rice across diverse regions, all without the need for phenological knowledge or a training dataset. Consequently, it holds substantial promise for efficiently mapping paddy rice on a large spatial scale. The source code used in this study is available at https://code.earthengine.google.com/f82cf10cad64fa3f971ae99027001a6e.

Tight conic approximation of testing regions for quantum statistical models and measurements

Quantum statistical models (i.e., families of normalized density matrices) and quantum measurements (i.e., positive operator-valued measures) can be regarded as linear maps: the former, mapping the space of effects to the space of probability distributions; the latter, mapping the space of states to the space of probability distributions. The images of such linear maps are called the testing regions of the corresponding model or measurement. Testing regions are notoriously impractical to treat analytically in the quantum case. Our first result is to provide an implicit outer approximation of the testing region of any given quantum statistical model or measurement in any finite dimension: namely, a region in probability space that contains the desired image, but is defined implicitly, using a formula that depends only on the given model or measurement. The outer approximation that we construct is minimal among all such outer approximations, and close, in the sense that it becomes the maximal inner approximation up to a constant scaling factor. Finally, we apply our approximation to provide sufficient conditions, that can be tested in a semi-device-independent way, for the ability to transform one quantum statistical model or measurement into another.

Oxygen extraction fraction mapping based combining quantitative susceptibility mapping and quantitative blood oxygenation level-dependent imaging model using multi-delay PCASL

Background and purposeThe oxygen extraction fraction is an essential biomarker for the assessment of brain metabolism. A recently proposed method combined with quantitative susceptibility mapping and quantitative blood oxygen level-dependent magnitude enables noninvasive mapping of the oxygen extraction fraction. Our study investigated the oxygen extraction fraction mapping variations of single-delay and multi-delay arterial spin-labeling. Materials and methodsA total of twenty healthy participants were enrolled. The multi-echo spoiled gradient-echo, multi-delay arterial spin-labeling, and magnetization-prepared rapid gradient echo sequences were acquired at 3.0 T. The mean oxygen extraction fraction was generated under a single delay time of 1780 ms, multi-delay arterial spin-labeling of transit-corrected cerebral blood flow, and multi-delay arterial spin-labeling of arterial cerebral blood volume. The results were compared via paired t tests and the Wilcoxon test. Linear regression analyses were used to investigate the relationships among the oxygen extraction fraction, cerebral blood flow, and venous cerebral blood volume. ResultsThe oxygen extraction fraction estimate with multi-delay arterial spin-labeling yielded a significantly lower value than that with single-delay arterial spin-labeling. The average values for the whole brain under single-delay arterial spin-labeling, multi-delay arterial spin-labeling of transit-corrected cerebral blood flow, and multi-delay arterial spin-labeling of arterial cerebral blood volume were 41.5 ± 1.7 % (P < 0.05), 41.3 ± 1.9 % (P < 0.001), and 40.9 ± 1.9 % (N = 20), respectively. The oxygen extraction fraction also showed a significant inverse correlation with the venous cerebral blood volume under steady-state conditions when multi-delay arterial spin-labeling was used (r = 0.5834, p = 0.0069). ConclusionThese findings suggest that the oxygen extraction fraction is significantly impacted by the arterial spin-labeling methods used in the quantitative susceptibility mapping plus the quantitative blood oxygen level-dependent model, indicating that the differences should be accounted for when employing oxygen extraction fraction mapping based on this model in diseases.

Magnetic Resonance Assessment of Bone Quality in Metabolic Bone Diseases.

Metabolic bone diseases (MBDs) are a diverse group of diseases, affecting the mass or structure of bones and leading to reduced bone quality. Parameters representing different aspects of bone health can be obtained from various magnetic resonance imaging (MRI) methods such as proton MR spectroscopy, as well as chemical shift encoding-based water-fat imaging, that have been frequently applied to study bone marrow in particular. Furthermore, T2* mapping and high-resolution trabecular bone imaging have been implemented to study bone microstructure. In addition, quantitative susceptibility mapping and ultrashort echo time imaging are used for trabecular and cortical bone assessment. This review offers an overview of technical aspects, as well as major clinical applications and derived main findings, for MRI-based assessment of bone quality in MBDs. It focuses on osteoporosis as the most common MBD.

Lung-resident alveolar macrophages regulate the timing of breast cancer metastasis.

Breast disseminated cancer cells (DCCs) can remain dormant in the lungs for extended periods, but the mechanisms limiting their expansion are not well understood. Research indicates that tissue-resident alveolar macrophages suppress breast cancer metastasis in lung alveoli by inducing dormancy. Through ligand-receptor mapping and intravital imaging, it was found that alveolar macrophages express transforming growth factor (TGF)-β2. This expression, along with persistent macrophage-cancer cell interactions via the TGF-βRIII receptor, maintains cancer cells in a dormant state. Depleting alveolar macrophages or losing the TGF-β2 receptor in cancer cells triggers metastatic awakening. Aggressive breast cancer cells are either suppressed by alveolar macrophages or evade this suppression by avoiding interaction and downregulating the TGF-β2 receptor. Restoring TGF-βRIII in aggressive cells reinstates TGF-β2-mediated macrophage growth suppression. Thus, alveolar macrophages act as a metastasis immune barrier, and downregulation of TGF-β2 signaling allows cancer cells to overcome macrophage-mediated growth suppression.

Unipolar voltage electroanatomic mapping detects structural atrial remodeling identified by LGE-MRI

BackgroundIn atrial fibrillation (AF) management, understanding left atrial (LA) substrate is crucial. While both electroanatomic mapping (EAM) and late gadolinium enhancement magnetic resonance imaging (LGE-MRI) are accepted methods for assessing the atrial substrate and are associated with ablation outcome, recent findings have highlighted discrepancies between low-voltage areas (LVAs) in EAM and LGE areas. ObjectiveThe purpose of this study was to explore the relationship between LGE regions and unipolar and bipolar LVAs using multipolar high-density mapping. MethodsTwenty patients scheduled for AF ablation underwent preablation LGE-MRI. LA segmentation was conducted using a deep learning approach, which subsequently generated a 3-dimensional mesh integrating the LGE data. High-density EAM was performed in sinus rhythm for each patient. The electroanatomic map and LGE-MRI mesh were coregistered. LVAs were defined using cutoffs of 0.5 mV for bipolar voltage and 2.5 mV for unipolar voltage. The correspondence between LGE areas and LVAs in the LA was analyzed using confusion matrices and performance metrics. ResultsA considerable 87.3% of LGE regions overlapped with unipolar LVAs, compared with only 16.2% overlap observed with bipolar LVAs. Across all performance metrics, unipolar LVAs outperformed bipolar LVAs in identifying LGE areas (precision: 78.6% vs 61.1%; sensitivity: 87.3% vs 16.2%; F1 score: 81.3% vs 26.0%; accuracy: 74.0% vs 35.3%). ConclusionOur findings demonstrate that unipolar LVAs strongly correlate with LGE regions. These findings support the integration of unipolar mapping alongside bipolar mapping into clinical practice. This would offer a nuanced approach to diagnose and manage AF by revealing critical insights into the complex architecture of the atrial substrate.

Use of multiparametric MRI to noninvasively assess iodinated contrast-induced acute kidney injury

PurposeTo gauge the utility of multiparametric MRI in characterizing pathologic changes after iodinated contrast-induced acute kidney injury (CI-AKI) in rats. MethodsWe randomly grouped 24 rats injected with 8 g iodine/kg of body weight (n = 6 each) and 6 rats injected with saline as controls. All rats underwent T1, T2 mapping and diffusion kurtosis imaging (DKI) after contrast injection at 0 (control), 1, 3, 7, 13 days. T1, T2, and mean kurtosis (MK) values were performed in renal outer/inner stripes of outer medulla (OSOM and ISOM) and cortex (CO), and their diagnosis performance for CI-AKI also been evaluated. Serum creatinine (SCr), insulin-like growth factor-binding protein 7 (IGFBP7), tissue inhibitor metalloproteinase 2 (TIMP-2), aquaporin-1 (AQP1), α-smooth muscle actin (α-SMA), and histologic indices were examined. ResultsCompared with controls, urinary concentrations of both TIMP-2 and IGFBP7 were obviously elevated from Day 1 to Day 13 (all p < 0.05). T2 values were significantly higher than control group for Days 1 and 3, and T1 and MK increased were more remarkable at all time points (Days 1–13) in CI-AKI (all p < 0.05) than control group. Changes in T1 and MK strongly correlated with renal injury scores of all anatomical compartments and with expression levels of AQP1 and moderately correlated with α-SMA. Changes in T2 values correlating moderately with renal scores of CO, ISOM and OSOM and AQP1. The MK obtained the highest area under the receiver operating characteristic (ROC) curve of 0.846 with a sensitivity of 70.8 % and specificity of 88.9 %. ConclusionsCombined use of multiparametric MRI could be a valid noninvasive method for comprehensive monitoring of CI-AKI. Among these parameters, MK may achieve the best diagnostic performance for CI-AKI.

High-resolution anionic velocity map imaging apparatus for dissociative electron attachment dynamics study.

Dissociative electron attachment (DEA) of a molecular target XY, e- + XY → XY- → X + Y-, is an important process in plasma, atmosphere, interstellar space, and ionizing radiation. DEA dynamics, i.e., the formation and fragmentation of an electron-molecule resonant complex, can be unveiled by measuring the product Y- with the velocity map imaging (VMI) technique. However, it is still challenging to achieve a high-resolution VMI measurement. Recently, we developed a high-resolution DEA apparatus that combined the VMI technique with a trochoidal electron monochromator. The energy spread (around 500meV) of thermally emitted incident electrons can be reduced remarkably, but the monochromatized electrons become diffuse again in energy when being pulsed with an electric pulse applied on the grid electrode because the electron beam must be pulsed in the VMI measurement. Now this long-standing technical contradiction is settled by introducing a parallel resistance-capacitor circuit to the electrode of an electron gun. A delay-line detector is used for the VMI measurement, which allows the three-dimensional velocity or momentum images of multiple anionic yields to be recorded efficiently. Our high-resolution VMI apparatus works at a pulse frequency of 5kHz and an energy spread of about 120-150meV, and its credible performances are exhibited by the measurements of the DEA processes of CO(a3Π) and NO2.

Role of diffusion weighted imaging in assessment of anterior cruciate ligament pathology

Background. The anterior cruciate ligament (ACL) is a structure that is vital to preserving the knee's normal stability. However, because the ACL is the ligament that sustains injuries the most frequently, it is essential to distinguish between complete and incomplete tears in order to treat patients with incomplete tears without surgery. To diagnose cruciate ligament tears, knee joint magnetic resonance imaging (MRI) is frequently used. But sometimes it's difficult because edema may hide the ligament fibers. ADC mapping may be useful to confirm whether or not the ligament is continuous for an appropriate diagnosis of incomplete tears because it has been demonstrated that ligament fibers are better visible on diffusion weighted imaging (DWI) and ADC mapping. Objective. To ascertain how anterior cruciate ligament (ACL) tears are diagnosed and classified as partial or complete using diffusion-weighted (DW) magnetic resonance imaging (MRI) and to compare it with conventional MRI sequences. Results. For partial tears, 10 cases (50%) were identified using arthroscopy/follow-up, while observer 1 identified 12 cases (60%) and observer 2 identified 9 cases (45%) using DWI/ADC. For complete tears, 10 cases (50%) were identified using arthroscopy/follow-up, while observer 1 identified 8 cases (40%) and observer 2 identified 11 cases (55%) using DWI/ADC. Conclusions. DWI and ADC are useful tools for diagnosing tears, particularly complete tears, but that caution should be exercised when using these techniques to diagnose partial tears.

Transparent MXene Microelectrode Arrays for Multimodal Mapping of Neural Dynamics.

Transparent microelectrode arrays have proven useful in neural sensing, offering a clear interface for monitoring brain activity without compromising high spatial and temporal resolution. The current landscape of transparent electrode technology faces challenges in developing durable, highly transparent electrodes while maintaining low interface impedance and prioritizing scalable processing and fabrication methods. To address these limitations, we introduce artifact-resistant transparent MXene microelectrode arrays optimized for high spatiotemporal resolution recording of neural activity. With 60% transmittance at 550 nm, these arrays enable simultaneous imaging and electrophysiology for multimodal neural mapping. Electrochemical characterization shows low impedance of 563 ± 99 kΩ at 1 kHz and a charge storage capacity of 58 mC cm⁻² without chemical doping. In vivo experiments in rodent models demonstrate the transparent arrays' functionality and performance. In a rodent model of chemically-induced epileptiform activity, we tracked ictal wavefronts via calcium imaging while simultaneously recording seizure onset. In the rat barrel cortex, we recorded multi-unit activity across cortical depths, showing the feasibility of recording high-frequency electrophysiological activity. The transparency and optical absorption properties of Ti₃C₂Tx MXene microelectrodes enable high-quality recordings and simultaneous light-based stimulation and imaging without contamination from light-induced artifacts.

Snap&amp;Nav: Smartphone-based Indoor Navigation System For Blind People via Floor Map Analysis and Intersection Detection

We present Snap&amp;Nav, a navigation system for blind people in unfamiliar buildings, without prebuilt digital maps. Instead, the system utilizes the floor map as its primary information source for route guidance. The system requires a sighted assistant to capture an image of the floor map, which is analyzed to create a node map containing intersections, destinations, and current positions on the floor. The system provides turn-by-turn navigation instructions while tracking users' positions on the node map by detecting intersections. Additionally, the system estimates the scale difference of the node map to provide distance information. Our system was validated through two user studies with 20 sighted and 12 blind participants. Results showed that sighted participants processed floor map images without being accustomed to the system, while blind participants navigated with increased confidence and lower cognitive load compared to the condition using only cane, appreciating the system's potential for use in various buildings.

Prompt-Based Modality Bridging for Unified Text-to-Face Generation and Manipulation

Text-driven face image generation and manipulation are significant tasks. However, such tasks are quite challenging due to the gap between text and image modalities. It is difficult to utilize current methods to deal with both of the two problems because these methods are usually designed for one certain task, limiting their application in real scenarios. To address the two problems in one framework, we propose a U nified P rompt-based C ross- M odal Frame work (UPCM-Frame) to bridge the gap between the text modality and image modality with CLIP and StyleGAN, which are two large-scale pre-trained models. The proposed framework is combined with two main modules: a Text Embedding-to-Image Embedding projection module based on a special prompt embedding pair, and a projection module mapping Image Embeddings to semantically aligned StyleGAN Embeddings which can be used in both image generation and manipulation. The proposed framework is able to handle complicated descriptions and generate impressive results with high quality due to the utilization of large-scale pre-trained models. In order to demonstrate the effectiveness of the proposed method in the two tasks, we conduct experiments to evaluate the results of our method both quantitatively and qualitatively.

The HHMP Decomposition of the Permutohedron and Degenerations of Torus Orbits in Flag Varieties

Abstract Let $Z\subset \operatorname{Fl}(n)$ be the closure of a generic torus orbit in the full flag variety. Anderson–Tymoczko express the cohomology class of $Z$ as a sum of classes of Richardson varieties. Harada–Horiguchi–Masuda–Park give a decomposition of the permutohedron, the moment map image of $Z$, into subpolytopes corresponding to the summands of the Anderson–Tymoczko formula. We construct an explicit toric degeneration inside $\operatorname{Fl}(n)$ of $Z$ into Richardson varieties, whose moment map images coincide with the HHMP decomposition, thereby obtaining a new proof of the Anderson–Tymoczko formula.

Enhanced hypersensitive (5D0→7F2) transition characteristics of Eu3+ doped β-Ga2O3 microrods

Exploring and realizing the luminescence characteristics of rare earth metal (RE) ions doped gallium oxide (Ga2O3) is crucial for developing optoelectronic device applications. The current research used the solid-state reaction approach to synthesize Ga2O3 microrods doped with various europium (Eu3+) concentrations (0.1, 0.2, 0.3, 0.5, 0.75, and 1 mol). X-ray diffraction (XRD) and Raman spectral analyses confirm the monoclinic structure of β-Ga2O3. The intensity of the Raman phonon modes decreased and a peak shift was observed for Eu:β-Ga2O3. The electron microscopy (SEM, TEM) images depicted a nearly uniform distribution of microrods for undoped and Eu:β-Ga2O3 samples. The interplanar distance (d = 0.290 nm, 0.561 nm, and 0.433 nm), from HR-TEM images, corresponding to (0 0 4), (1 0 0), and (1 0 2) crystallographic orientations confirm the monoclinic structure of β-Ga2O3. The elemental mapping images showed a nearly homogeneous Ga, O, and Eu distribution. The UV–visible diffuse reflectance spectroscopy (UV-DRS) showed a notable reduction in the bandgap as the Eu3+ concentration increased. The emission spectra of Eu: β-Ga2O3 microrods showed a narrow red emission at 612 nm (5D0 → 7F2), which relates to the 5D0 → 7Fj (j = 0, 1, 2, 3) energy level arising from an intra-4f transition of Eu3+ ions upon 394 and 465 nm excitation. The red emission was found to increase with Eu content up to 0.5 mol.%. A quenching of emission due to the multipole–multipole interactions was obtained beyond 0.5 mol.% of Eu. The absolute quantum yield (η) calculated for Eu: β-Ga2O3 (0.5 mol.%) was 3.82 %. The luminescence decay curve using the bi-exponential fit and the average lifetime (τ) of the Eu: β-Ga2O3 (0.5 mol.%) was found to be ∼0.172 ms. CIE chromaticity and correlated color temperature analyses of Eu:β-Ga2O3 microrods yielded a red emission with a superior color purity (93 %). The obtained results suggest that Eu:β-Ga2O3 (0.5 wt.%) microrods could be one of the potential candidates for red light sources.

Preoperative prediction of lymph node metastasis in endometrial cancer patients via an intratumoral and peritumoral multiparameter MRI radiomics nomogram.

While lymph node metastasis (LNM) plays a critical role in determining treatment options for endometrial cancer (EC) patients, the existing preoperative methods for evaluating the lymph node state are not always satisfactory. This study aimed to develop and validate a nomogram based on intra- and peritumoral radiomics features and multiparameter magnetic resonance imaging (MRI) features to preoperatively predict LNM in EC patients. Three hundred and seventy-four women with histologically confirmed EC were divided into training (n = 220), test (n = 94), and independent validation (n = 60) cohorts. Radiomic features were extracted from intra- and peritumoral regions via axial T2-weighted imaging (T2WI) and apparent diffusion coefficient (ADC) mapping. A radiomics model (annotated as the Radscore) was established using the selected features from different regions. The clinical parameters were statistically analyzed. A nomogram was developed by combining the Radscore and the most predictive clinical parameters. Decision curve analysis (DCA) and the net reclassification index (NRI) were used to assess the clinical benefit of using the nomogram. Nine radiomics features were ultimately selected from the intra- and peritumoral regions via ADC mapping and T2WI. The nomogram combining the Radscore, serum CA125 level, and tumor area ratio achieved the highest AUCs in the training, test and independent validation sets (nomogram vs. Radscore vs. clinical model: 0.878 vs. 0.850 vs. 0.674 (training), 0.877 vs. 0.838 vs. 0.668 (test), and 0.864 vs. 0.836 vs. 0.618 (independent validation)). The DCA and NRI results revealed the nomogram had greater diagnostic performance and net clinical benefits than the Radscore alone. The combined intra- and peritumoral region multiparameter MRI radiomics nomogram showed good diagnostic performance and could be used to preoperatively predict LNM in patients with EC.