Electron-proton relaxation in hot-dense plasmas with a screened quantum statistical potential.

Modeling the nonequilibrium process between ions and electrons is of great importance in laboratory fusion ignition, laser-plasma interaction, and astrophysics. For hot and dense plasmas, theoretical descriptions of Coulomb collisions remain complicated due to quantum effect at short distances and screening effect at long distances. In this paper, we propose an analytical screened quantum statistical potential that takes into account both the short-range quantum diffraction effect and the long-range screening effect. By implementing the newly developed potential into the binary scattering framework, the electron-proton temperature relaxation in hot-dense hydrogen plasmas is investigated. In both the classical and quantum limits, analytical expressions for the Coulomb logarithm have been obtained, which are generally embedded in an asymptotic matching formula. Quantitative comparisons with molecular dynamics simulations and recent OMEGA experiments demonstrate that the present modeling is well suited to describe the temperature relaxation process between electrons and ions in hot-dense plasmas.

ETHE1 dampens colorectal cancer angiogenesis by promoting TC45 Dephosphorylation of STAT3 to inhibit VEGF-A expression.

Angiogenesis is critical for colorectal cancer (CRC) progression, but its mechanisms remain unclear. Here, we reveal that ethylmalonic encephalopathy protein 1 (ETHE1), an essential enzyme in hydrogen sulfide catabolism, inhibits VEGF-A expression and tumor angiogenesis in vitro and in vivo. Moreover, we find that this biological function of ETHE1 depends on the STAT3/VEGF-A pathway. Further investigation demonstrates that ETHE1 promotes the interaction between T cell protein tyrosine phosphatase (TC45) and STAT3, resulting in decreased STAT3 phosphorylation and inhibition of the STAT3 signaling pathway. In clinical samples, we find that ETHE1 is downregulated in CRC and positively correlates with survival outcomes of CRC patients. Meanwhile, the negative correlation of ETHE1 and VEGF-A expression is verified in CRC specimens, and the patients with low ETHE1 and high VEGF-A expression exhibits poorer prognosis. Collectively, our study identifies ETHE1 as a novel regulator of tumor angiogenesis, implying its potential as a prognostic biomarker and promising antiangiogenic target for CRC patients.

Regulatory effect of rapamycin on recruitment and function of myeloid-derived suppressor cells in heart failure.

BACKGROUND: Immune response and inflammation play important roles in the physiological and pathophysiological processes of heart failure (HF). In our previous study, myeloid-derived suppressor cells (MDSCs), a heterogeneous group of immature myeloid cells with anti-inflammatory and immunosuppressive functions, were shown to exert cardioprotective effects in HF. The pharmacological targeting of MDSCs using rapamycin may emerge as a promising strategy for the prevention and treatment of HF. However, the specific mechanisms underlying rapamycin-induced MDSC accumulation remain unclear. Our study aimed to clarify the effects of rapamycin on the recruitment and function of MDSCs in HF, exploring new therapeutic options for the prevention and treatment of HF. METHODS: We used transverse aortic constriction surgery and isoproterenol injection to establish HF models. Flow cytometry, reverse transcription polymerase chain reaction, transcriptomics and western blot were used to explore the regulation of rapamycin on recruitment and function of MDSCs in HF. Furthermore, rapamycin and granulocyte-macrophage colony-stimulating factor (GM-CSF) were combined to induce exogenous MDSCs from bone marrow cells. RESULTS: Rapamycin promotes the recruitment of MDSCs by inhibiting their maturation and differentiation via suppression of the Wnt signaling in HF mice and enhanced the immunosuppressive function of MDSCs via the NF-κB signaling. Furthermore, exogenous MDSCs induced by rapamycin and GM-CSF can significantly alleviate transverse aortic constriction-induced cardiac dysfunction. CONCLUSIONS: The pharmacological targeting of MDSCs using rapamycin is a promising strategy for the prevention and treatment of HF.

Location matters: altered interhemispheric homotopic connectivity in post-stroke dyskinesia.

Background: Motor impairment is the most prevalent consequence following a stroke. Interhemispheric homotopic connectivity, which varies regionally and hierarchically along the axis of the somatomotor-association cortex, plays a critical role in sustaining normal motor functions. However, the impact of strokes occurring in various locations on homotopic connectivity is not fully understood. This study aimed to explore how motor deficits resulting from acute strokes in different locations influence homotopic connectivity. Methods: Eighty-four acute ischemic stroke patients with dyskinesia were recruited and divided into four demographically-matched subgroups based on stroke locations: Group 1 (G1; frontoparietal, n = 15), Group 2 (G2; radiation coronal, n = 16), Group 3 (G3; basal ganglia, n = 30), and Group 4 (G4; brain stem, n = 23). An additional 37 demographically-matched healthy controls were also recruited in the study. Multimodal MRI data, motor function assessments, and cognitive tests were gathered for analysis. Interhemispheric homotopic functional and structural connectivity were measured using resting-state functional MRI and diffusion tensor imaging, respectively. These measurements were then correlated with motor function scores to investigate the relationships. Results: Voxel-mirrored homotopic connectivity (VMHC) analysis showed that strokes in the frontoparietal and basal ganglia regions led to diminished homotopic connectivity in the somatosensory/motor cortex. In contrast, strokes in the radiation coronal and brainstem regions affected subcortical motor circuits. Structural homotopic connectivity analysis using diffusion tensor imaging showed that frontoparietal and basal ganglia strokes predominantly affected association fibers, while radiation coronal and brainstem strokes caused widespread disruption in the integrity of both cortical-cortical and cortical-subcortical white matter fibers. Correlation analyses demonstrated significant associations between the Fugl-Meyer Assessment (FMA), Modified Barthel Index (MBI), and National Institutes of Health Stroke Scale (NIHSS) scores with the VMHC in the inferior temporal gyrus for G1 (G1; r = 0.838, p < 0.001; r = 0.793, p < 0.001; and r = -0.834, p < 0.001, respectively). No statistically significant associations were observed in Groups 2, 3, and 4. Conclusion: Our results suggest that motor deficits following strokes in various regions involve distinct pathways from cortical to subcortical areas. Alterations in lesion topography and regional functional homotopy provide new insights into the understanding of neural underpinnings of post-stroke dyskinesia.

Arterial transit artifacts and carotid Plaque-RADS may predict symptoms in patients with carotid stenosis.

AIM: To analyze the correlation of carotid stenosis severity, the Plaque Reporting and Data System (RADS) score, arterial transit artifacts (ATAs), and cerebral blood flow (CBF) with clinical cerebral ischemic symptoms in patients with carotid artery stenosis (CAS). MATERIALS AND METHODS: Sixty-one patients with unilateral internal carotid artery stenosis or occlusion (≥50% stenosis) diagnosed by ultrasound, Computed Tomography(CT) angiography, or Magnetic Resonance(MR) angiography in Yichang City Central People's Hospital from January 2022 to February 2024 were retrospectively enrolled and divided into two groups according to the presence or absence of symptoms. Both groups underwent MR plaque imaging and arterial spin labeling (ASL)-based 3.0 T MRI to compare the differences in stenosis degree, Plaque-RADS score, ATA grade, and CBF between the two groups. Binary regression analysis was used to identify the parameters with statistically significant differences between the two groups and to evaluate their diagnostic efficacy using the area under the workup curve of the subjects. RESULTS: The Plaque-RADS score, ATA grade, and CBF differences in the anterior cerebral artery(ACA)blood supply region were correlated with symptoms, and the areas under the ROC curves for the CBF differences in the ACA blood supply region, Plaque-RADS score, ATA grade and a joint model that combines all three to predict symptoms in CAS patients were 0.672, 0.796, 0.788 and 0.919, respectively. CONCLUSIONS: CBF, Plaque-RADS and ATAs were identified as independent risk factors for symptoms in patients with CAS and have a certain predictive value for symptoms, and the combined predictive value is greater, potentially providing a more effective imaging modality for clinical treatment and evaluation.

Effects of the epiphytic patterns on endophytes and metabolites of Dendrobium nobile Lindl.

Introduction: Dendrobium is an epiphytic herb plant with neuroprotective, gastroprotective, anti-inflammatory, and immunomodulatory effects. It is often found attached to tree trunks or rocks. With the development of the dendrobium industry, numerous epiphytic patterns exist, such as crushed stone, stump, and sawdust. The study of metabolites and endophytes of D. nobile under different epiphytic patterns, which revealed the effects of epiphytic patterns on D. nobile from the perspectives of metabolomics and microbiology, is of great significance for the healthy development of D. nobile. Methods: In the study, the D. nobile under five epiphytic patterns grown in the same environment were selected. The metabolites were investigated by widely targeted metabolomics, and the endophytes were sequenced using high-throughput sequencing methods. Then, a correlation analysis between the different metabolites and endophytes was performed. Results: A total of 1,032 metabolites were annotated in D. nobile. There are more flavonoids and phenolic acids accumulated on the epiphytic pattern of Danxia stone, whereas the accumulation of lipids on the other epiphytic patterns and 16 differential metabolites was screened out. The endophyte composition of D. nobile was dominated by Proteobacteria, Actinomycetes, unidentified bacteria, Firmicutes, and Cyanobacteria. For endophytic fungi, Basidiomycota and Ascomycota were the dominant phyla of D. nobile. The relative abundance of Spirosoma, Nocardioides, and Arrhenia in the Danxia stone was significantly higher than that of other epiphytic patterns. According to correlation analysis, we found a significant correlation between differential metabolites and Spirosoma, Nocardioides, and Arrheni. Discussion: This study confirmed that Dendrobium quality was affected by its epiphytic patterns and revealed its possible causes from a microbiological point of view.

Development and Validation of a Deep Learning Model to Reduce the Interference of Rectal Artifacts in MRI-based Prostate Cancer Diagnosis.

Purpose To develop an MRI-based model for clinically significant prostate cancer (csPCa) diagnosis that can resist rectal artifact interference. Materials and Methods This retrospective study included 2203 male patients with prostate lesions who underwent biparametric MRI and biopsy between January 2019 and June 2023. Targeted adversarial training with proprietary adversarial samples (TPAS) strategy was proposed to enhance model resistance against rectal artifacts. The automated csPCa diagnostic models trained with and without TPAS were compared using multicenter validation datasets. The impact of rectal artifacts on the diagnostic performance of each model at the patient and lesion levels was compared using the area under the receiver operating characteristic curve (AUC) and the area under the precision-recall curve (AUPRC). The AUC between models was compared using the DeLong test, and the AUPRC was compared using the bootstrap method. Results The TPAS model exhibited diagnostic performance improvements of 6% at the patient level (AUC: 0.87 vs 0.81, P < .001) and 7% at the lesion level (AUPRC: 0.84 vs 0.77, P = .007) compared with the control model. The TPAS model demonstrated less performance decline in the presence of rectal artifact-pattern adversarial noise than the control model (ΔAUC: -17% vs -19%, ΔAUPRC: -18% vs -21%). The TPAS model performed better than the control model in patients with moderate (AUC: 0.79 vs 0.73, AUPRC: 0.68 vs 0.61) and severe (AUC: 0.75 vs 0.57, AUPRC: 0.69 vs 0.59) artifacts. Conclusion This study demonstrates that the TPAS model can reduce rectal artifact interference in MRI-based csPCa diagnosis, thereby improving its performance in clinical applications. Keywords: MR-Diffusion-weighted Imaging, Urinary, Prostate, Comparative Studies, Diagnosis, Transfer Learning Clinical trial registration no. ChiCTR23000069832 Supplemental material is available for this article. Published under a CC BY 4.0 license.

Characterizing the impacts of dataset imbalance on single-cell data integration.

Computational methods for integrating single-cell transcriptomic data from multiple samples and conditions do not generally account for imbalances in the cell types measured in different datasets. In this study, we examined how differences in the cell types present, the number of cells per cell type and the cell type proportions across samples affect downstream analyses after integration. The Iniquitate pipeline assesses the robustness of integration results after perturbing the degree of imbalance between datasets. Benchmarking of five state-of-the-art single-cell RNA sequencing integration techniques in 2,600 integration experiments indicates that sample imbalance has substantial impacts on downstream analyses and the biological interpretation of integration results. Imbalance perturbation led to statistically significant variation in unsupervised clustering, cell type classification, differential expression and marker gene annotation, query-to-reference mapping and trajectory inference. We quantified the impacts of imbalance through newly introduced properties-aggregate cell type support and minimum cell type center distance. To better characterize and mitigate impacts of imbalance, we introduce balanced clustering metrics and imbalanced integration guidelines for integration method users.

Prediction of the Nottingham prognostic index and molecular subtypes of breast cancer through multimodal magnetic resonance imaging.

PURPOSE: To explore the ability of intravoxel incoherent motion (IVIM), diffusion kurtosis imaging (DKI) and background parenchyma enhancement (BPE) to predict the Nottingham prognostic index (NPI) and molecular subtypes of breast cancer (BC). MATERIALS AND METHODS: In this study, 93 patients with BC were included, and they all underwent DKI, IVIM and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) examinations. The corresponding mean kurtosis value (MK), pure diffusion (MD), perfusion fraction (f), pseudo diffusion coefficient (D*), true diffusion coefficient (D), and BPE were measured. We used logistic regression analysis to investigate the relevance between the NPI, molecular subtypes and variables. The diagnostic efficacy was analyzed using receiver operating characteristic curves (ROC). RESULTS: The MD and D values of the high-level NPI group were significantly lower than those of the low-level NPI group (p < 0.01), and the f value of the high-level NPI group was obviously higher than that of low-level NPI group (p < 0.001). The area under curve (AUC) of the combined model (f + D) was 0.824. Comparing with non-Luminal subtypes, the Luminal subtypes showed obviously lower MK, f and D*, and the AUC of the combined model (MK + f + D*) was 0.785. In comparison to other subtypes, the MK and D* values of triple-negative subtype were higher than other subtypes, and the combined model (MK + D*) represented an AUC of 0.865. CONCLUSION: The quantitative parameters of DKI and IVIM have vital value in predicting the NPI and molecular subtypes of BC, while BPE could not provide additional information. Besides, these combined models can obviously improve the prediction performance.

NSD2 methylates AROS to promote SIRT1 activation and regulates fatty acid metabolism-mediated cancer radiotherapy.

Fatty acid metabolism plays a critical role in both tumorigenesis and cancer radiotherapy. However, the regulatory mechanism of fatty acid metabolism has not been fully elucidated. NSD2, a histone methyltransferase that catalyzes di-methylation of histone H3 at lysine 36, has been shown to play an essential role in tumorigenesis and cancer progression. Here, we show that NSD2 promotes fatty acid oxidation (FAO) by methylating AROS (active regulator of SIRT1) at lysine 27, facilitating the physical interaction between AROS and SIRT1. The mutation of lysine 27 to arginine weakens the interaction between AROS and SIRT1 and impairs AROS-SIRT1-mediated FAO. Additionally, we examine the effect of NSD2 inhibition on radiotherapy efficacy and find an enhanced effectiveness of radiotherapy. Together, our findings identify a NSD2-dependent methylation regulation pattern of the AROS-SIRT1 axis, suggesting that NSD2 inhibition may be a potential adjunct for tumor radiotherapy.

Nanograded artificial nacre with efficient energy dissipation.

The renowned mechanical performance of biological ceramics can be attributed to their hierarchical structures, wherein structural features at the nanoscale play a crucial role. However, nanoscale features, such as nanogradients, have rarely been incorporated in biomimetic ceramics because of the challenges in simultaneously controlling the material structure at multiple length scales. Here, we report the fabrication of artificial nacre with graphene oxide nanogradients in its aragonite platelets through a matrix-directed mineralization method. The gradients are formed via the spontaneous accumulation of graphene oxide nanosheets on the surface of the platelets during the mineralization process, which then induces a lateral residual stress field in the platelets. Nanoindentation tests and mercury intrusion porosimetry demonstrate that the material's energy dissipation is enhanced both intrinsically and extrinsically through the compressive stress near the platelet surface. The energy dissipation density reaches 0.159 ± 0.007 nJ/µm3, and the toughness amplification is superior to that of the most advanced ceramics. Numerical simulations also agree with the finding that the stress field notably contributes to the overall energy dissipation. This work demonstrates that the energy dissipation of biomimetic ceramics can be further increased by integrating design principles spanning multiple scales. This strategy can be readily extended to the combinations of other structural models for the design and fabrication of structural ceramics with customized and optimized performance.

SETDB1 Methylates MCT1 Promoting Tumor Progression by Enhancing the Lactate Shuttle.

MCT1 is a critical protein found in monocarboxylate transporters that plays a significant role in regulating the lactate shuttle. However, the post-transcriptional modifications that regulate MCT1 are not clearly identified. In this study, it is reported that SETDB1 interacts with MCT1, leading to its stabilization. These findings reveal a novel post-translational modification of MCT1, in which SETDB1 methylation occurs at K473 in vitro and in vivo. This methylation inhibits the interaction between MCT1 and Tollip, which blocks Tollip-mediated autophagic degradation of MCT1. Furthermore, MCT1 K473 tri-methylation promotes tumor glycolysis and M2-like polarization of tumor-associated macrophages in colorectal cancer (CRC), which enhances the lactate shuttle. In clinical studies, MCT1 K473 tri-methylation is found to be upregulated and positively correlated with tumor progression and overall survival in CRC. This discovery suggests that SETDB1-mediated tri-methylation at K473 is a vital regulatory mechanism for lactate shuttle and tumor progression. Additionally, MCT1 K473 methylation may be a potential prognostic biomarker and promising therapeutic target for CRC.

PRMT5 methylating SMAD4 activates TGF-ß signaling and promotes colorectal cancer metastasis.

Perturbations in transforming growth factor-ß (TGF-ß) signaling can lead to a plethora of diseases, including cancer. Mutations and posttranslational modifications (PTMs) of the partner of SMAD complexes contribute to the dysregulation of TGF-ß signaling. Here, we reported a PTM of SMAD4, R361 methylation, that was critical for SMAD complexes formation and TGF-ß signaling activation. Through mass spectrometric, co-immunoprecipitation (Co-IP) and immunofluorescent (IF) assays, we found that oncogene protein arginine methyltransferase 5 (PRMT5) interacted with SMAD4 under TGF-ß1 treatment. Mechanically, PRMT5 triggered SMAD4 methylation at R361 and induced SMAD complexes formation and nuclear import. Furthermore, we emphasized that PRMT5 interacting and methylating SMAD4 was required for TGF-ß1-induced epithelial-mesenchymal transition (EMT) and colorectal cancer (CRC) metastasis, and SMAD4 R361 mutation diminished PRMT5 and TGF-ß1-induced metastasis. In addition, highly expressed PRMT5 or high level of SMAD4 R361 methylation indicated worse outcomes in clinical specimens analysis. Collectively, our study highlights the critical interaction of PRMT5 and SMAD4 and the roles of SMAD4 R361 methylation for controlling TGF-ß signaling during metastasis. We provided a new insight for SMAD4 activation. And this study indicated that blocking PRMT5-SMAD4 signaling might be an effective targeting strategy in SMAD4 wild-type CRC.

Higher magnetic susceptibility of globus pallidus in patients after macrocyclic GBCAs: assessment using quantitative susceptibility mapping.

BACKGROUND: As previous studies reported, gadolinium deposits in globus pallidus (GP) and dentate nucleus (DN) after repeated administrations of gadolinium-based contrast agents (GBCAs) and a signal intensity (SI) increase on T1-weighted images were related to linear GBCAs, not macrocyclic GBCAs. PURPOSE: To identify whether quantitative susceptibility mapping (QSM) could measure a subtle increase in magnetic susceptibility in DN and GP in patients after repeated administrations of gadoteric acid meglumine (Gd-DOTA). MATERIAL AND METHODS: In this study, 50 patients with cerebral tumors who had received at least three injections of Gd-DOTA (GBCA group) and 50 individuals without a history of GBCA injections (non-GBCA group) were included. The image data for QSM and T1-weighted images were reviewed. Spearman rank correlation was used to estimate the associations between the values (magnetic susceptibility of QSM and SI ratios of T1-weighted images) and the number of Gd-DOTA injections. RESULTS: The mean magnetic susceptibility of GP in GBCA group was 0.136 ± 0.031 ppm, which was significantly higher than that in control group (0.114 ± 0.030 ppm) (P = 0.001). In the GBCA group (n = 50), we found a substantial positive correlation between magnetic susceptibility of GP and the number of Gd-DOTA injections according to Spearman rank correlation coefficient (ρ = 0.673, P = 0.0001). There was a modest but significant correlation between magnetic susceptibility of DN and the number of Gd-DOTA injections (ρ = 0.311, P = 0.028). CONCLUSION: In comparison to the control group, the magnetic susceptibility of GP in the GBCA group was significantly higher and had a substantial positive association with the number of Gd-DOTA injections.

The Function and Therapeutic Implications of TNF Signaling in MDSCs.

Myeloid-derived suppressor cells (MDSCs) are a group of immature and heterogeneous myeloid cells with immunosuppressive functions. MDSCs play important roles in the pathogenesis of cancer, chronic inflammatory diseases, and many autoimmune disorders. The accumulation and activation of MDSCs can be regulated by tumor necrosis factor α (TNF-α). In this review, we summarize the roles played by TNF-α in the recruitment, immunosuppressive functions, and chemotaxis of MDSCs, and discuss the potential therapeutic effects of TNF-α upon these cells in tumor growth and some inflammatory disorders.

Comparing the diagnostic accuracy of PET and CMR for the measurement of left ventricular volumes and ejection fraction: a system review and meta-analysis.

BACKGROUND: Cardiac magnetic resonance (CMR) has been recognized as the gold standard for the evaluation of left ventricular (LV) function. Cardiac gated PET allows the simultaneous assessment of LV function with the evaluation of myocardial perfusion and metabolism. But the correlations between PET and CMR remain controversial. METHODS: We conducted a systematic electronic search of PubMed, Embase and the Cochrane Library . Forest plot, spearman correlation analysis and Bland-Altman analysis were used to evaluate the correlations between PET and CMR. RESULTS: Pooled analysis of 13 studies showed that PET underestimated left ventricular end-diastolic volumes (LVEDV) [mean difference (MD), -15.30; 95% confidence interval (CI), -23.10 to -7.50; P < 0.001] and left ventricular end-systolic volumes (LVESV) (MD, -6.20; 95% CI, -12.58 to 0.17; P = 0.06) but not left ventricular ejection fraction (LVEF) (MD, -0.35; 95% CI, -1.75 to 1.06; P = 0.63). Overall, there were very good correlations between PET and CMR measurements for LVEDV ( r , 0.897), LVESV ( r , 0.924) and LVEF ( r , 0.898). Subgroup analysis indicated that LVEDV ≥180 ml and LVEF <40% reduced the accuracy of PET, especially the measurement of LVEF ( r , LVEDV ≥180 vs . r , LVEDV < 180 : 0.821 vs. 0.944; r , LVEF < 40% vs . r , LVEF ≥40% : 0.784 vs. 0.901). CONCLUSIONS: Correlations between PET and CMR measurements of LVEDV, LVESV and LVEF were excellent, but these two methods could not be used interchangeably for accurate measurements of LV volume and LVEF in patients with significantly increased LV volume and decreased LVEF.

Mechanisms and Therapeutic Strategies of Viral Myocarditis Targeting Autophagy.

Viral myocarditis is caused by infection with viruses or bacteria, including coxsackievirus B3 (CVB3), and is characterized by acute or chronic inflammatory responses in the heart. The mortality associated with severe viral myocarditis is considerable. In some patients, viral myocarditis may develop into dilated cardiomyopathy or heart failure. Autophagy is involved in a wide range of physiological processes, including viral infection and replication. In the present review, we focus on the responses of cardiac tissues, cardiomyocytes, and cardiac fibroblasts to CVB3 infection. Subsequently, the effects of altered autophagy on the development of viral myocarditis are discussed. Finally, this review also examined and assessed the use of several popular autophagy modulating drugs, such as metformin, resveratrol, rapamycin, wortmannin, and 3-methyladenine, as alternative treatment strategies for viral myocarditis.

The appearance of magnetic susceptibility objects in SWI phase depends on object size: Comparison with QSM and CT.

PURPOSE: Tissue magnetic susceptibility sign can potentially be detected on susceptibility weighted imaging (SWI) phase (SW-P). This study aims to investigate its performance for depicting brain susceptibility structures. METHODS: A simulation was performed to depict magnetic susceptibility structures of various geometries on SW-P and quantitative susceptibility mapping (QSM). Brain MRI was performed on 25 subjects using SWI on a 3 T MRI system. QSM was generated from the same data. SW-P and QSM were analyzed according to radiological assessment for depicting globus pallidus nuclei, optic radiation white matter tracts, and lateral ventricular choroid plexus calcifications. In 11 of these subjects, CT was available and correlated with SW-P and QSM to assess their performance in quantifying calcifications in the choroid plexus. RESULTS: In simulation, the appearance of a sphere on SW-P ranged from centric nodule to mixed positive and negative values as the diameter increased. Large cylinders also appeared as mixed positive and negative values. In comparison, QSM correctly depicted the susceptibility distribution of all magnetic structures. On human brain images, SW-P depicted the globus pallidus and optic radiation with mixed positive and negative values, consistent with simulation, and small choroid plexus calcifications as either mixed positive and negative values or as centric nodules; QSM depicted all structures as solid structures with the expected signs. For measuring calcification in the choroid plexus, QSM vs CT linear regression had a higher coefficient of determination compared to SW-P vs CT and SW-P vs QSM. CONCLUSION: Appearance of susceptibility sources on SW-P changes with object size. This problem can be overcome using QSM.

Prognostic value of initial chest CT findings for clinical outcomes in patients with COVID-19.

Rationale: To identify whether the initial chest computed tomography (CT) findings of patients with coronavirus disease 2019 (COVID-19) are helpful for predicting the clinical outcome. Methods: A total of 224 patients with laboratory-confirmed COVID-19 who underwent chest CT examination within the first day of admission were enrolled. CT findings, including the pattern and distribution of opacities, the number of lung lobes involved and the chest CT scores of lung involvement, were assessed. Independent predictors of adverse clinical outcomes were determined by multivariate regression analysis. Adverse outcome were defined as the need for mechanical ventilation or death. Results: Of 224 patients, 74 (33%) had adverse outcomes and 150 (67%) had good outcomes. There were higher frequencies of more than four lung zones involved (73% vs 32%), both central and peripheral distribution (57% vs 42%), consolidation (27% vs 17%), and air bronchogram (24% vs 13%) and higher initial chest CT scores (8.6±3.4 vs 5.4±2.1) (P < 0.05 for all) in the patients with poor outcomes. Multivariate analysis demonstrated that more than four lung zones (odds ratio [OR] 3.93; 95% confidence interval [CI]: 1.44 to 12.89), age above 65 (OR 3.65; 95% CI: 1.11 to 10.59), the presence of comorbidity (OR 5.21; 95% CI: 1.64 to 19.22) and dyspnea on admission (OR 3.19; 95% CI: 1.35 to 8.46) were independent predictors of poor outcome. Conclusions: Involvement of more than four lung zones and a higher CT score on the initial chest CT were significantly associated with adverse clinical outcome. Initial chest CT findings may be helpful for predicting clinical outcome in patients with COVID-19.

Stochastic radiative transfer in random media: Pure absorbing cases.

We study stochastic radiation transport through random media in one dimension, in particular for pure absorbing cases. The statistical model to calculate the ensemble-averaged transmission for a binary random mixture is derived based on the cumulative probability density function (PDF) of optical depth, which is numerically simulated for both Markovian and non-Markovian mixtures by Monte Carlo calculations. We present systematic results about the influence of mixtures' stochasticity on the radiation transport. It is found that mixing statistics affects the ensemble-averaged intensities mainly due to the distribution of cumulative PDF at small optical depths, which explains well why the ensemble-averaged transmission is observed to be sensitive to chord length distribution and its variances. The effect of the particle size is substantial when the mixtures' correlation length is comparable to the mean free path of photons, which imprints a moderately broad transition region into the cumulative PDF. With the mixing probability increasing, the intensity decreases nearly exponentially, from which the mixing zone length can be approximately estimated. The impact of mixed configuration is also discussed, which is in line with previous results.