88 research outputs found

    Radiomics analysis for predicting malignant cerebral edema in patients undergoing endovascular treatment for acute ischemic stroke

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    PURPOSERadiomics analysis is a promising image analysis technique. This study aims to extract a radiomics signature from baseline computed tomography (CT) to predict malignant cerebral edema (MCE) in patients with acute anterior circulation infarction after endovascular treatment (EVT).METHODSIn this retrospective study, 111 patients underwent EVT for acute ischemic stroke caused by middle cerebral artery (MCA) and/or internal carotid artery occlusion. The participants were randomly divided into two datasets: the training set (n = 77) and the test set (n = 34). The clinico-radiological profiles of all patients were collected, including cranial non-contrast-enhanced CT, CT angiography, and CT perfusion. The MCA territory on non-contrast-enhanced CT images was segmented, and the radiomics features associated with MCE were analyzed. The clinico-radiological parameters related to MCE were also identified. In addition, a routine visual radiological model based on radiological factors and a combined model comprising radiomics features and clinico-radiological factors were constructed to predict MCE.RESULTSThe areas under the curve (AUCs) of the radiomics signature for predicting MCE were 0.870 (P < 0.001) and 0.837 (P = 0.002) in the training and test sets, respectively. The AUCs of the routine visual radiological model were 0.808 (P < 0.001) and 0.813 (P = 0.005) in the training and test sets, respectively. The AUCs of the model combining the radiomics signature and clinico-radiological factors were 0.924 (P < 0.001) and 0.879 (P = 0.001) in the training and test sets, respectively.CONCLUSIONA CT image-based radiomics signature is a promising tool for predicting MCE in patients with acute anterior circulation infarction after EVT. For clinicians, it may assist in diagnostic decision-making

    Prognostic role of iodine values for gastric cancer after neoadjuvant chemotherapy: a strong independent prognostic factor

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    PURPOSEWe aimed to systematically explore the value of iodine values calculated from dual-energy computed tomography (DECT) as potential prognostic factors for locally advanced gastric cancer (LAGC) patients undergoing neoadjuvant chemotherapy (NAC).METHODSEighty-five LAGC patients were examined using DECT before and after NAC and were divided into responders and non-responders based on the tumor regression grade (TRG). The iodine values including portal- and delayed-phase iodine uptake (IUp and IUd, mg/mL) and total iodine uptake (TIUp and TIUd, mg) were acquired. Correlations between the reduction ratios of iodine values and TRG were analyzed. The diagnostic performance of parameters for differentiating responders from non-responders was calculated. Kaplan–Meier method was used for survival analysis.RESULTSThe reduction ratios of total iodine uptake (%ΔTIUp and %ΔTIUd) were significantly correlated with TRG (P < .001). The ypN stage, %ΔTIUp, and %ΔTIUd were significant factors influencing progression-free survival (PFS) (P < .050). A value of %ΔTIUd ≤ 62.19% was associated with negative prognosis [relative risk (RR):2.103; P = 0.021], as was ypN stage (RR: 4.250; P = .003).CONCLUSIONIodine values (especially the TIU) are noninvasive quantitative parameters that are potentially helpful for evaluating the treatment response and survival prognosis of LAGC after NAC. %ΔTIUd represents a strong independent prognostic factor, increasing preoperative risk assessment performance

    Chemisorption Induced Formation of Biphenylene Dimer on Surfaces

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    We report an example that demonstrates the clear interdependence between surface-supported reactions and molecular adsorption configurations. Two biphenyl-based molecules with two and four bromine substituents, i.e. 2,2-dibromo-biphenyl (DBBP) and 2,2,6,6-tetrabromo-1,1-biphenyl (TBBP), show completely different reaction pathways on a Ag(111) surface, leading to the selective formation of dibenzo[e,l]pyrene and biphenylene dimer, respectively. By combining low-temperature scanning tunneling microscopy, synchrotron radiation photoemission spectroscopy, and density functional theory calculations, we unravel the underlying reaction mechanism. After debromination, a bi-radical biphenyl can be stabilized by surface Ag adatoms, while a four-radical biphenyl undergoes spontaneous intramolecular annulation due to its extreme instability on Ag(111). Such different chemisorption-induced precursor states between DBBP and TBBP consequently lead to different reaction pathways after further annealing. In addition, using bond-resolving scanning tunneling microscopy and scanning tunneling spectroscopy, we determine the bond length alternation of biphenylene dimer product with atomic precision, which contains four-, six-, and eight-membered rings. The four-membered ring units turn out to be radialene structures

    The possible mechanisms of ferroptosis in sepsis-associated acquired weakness

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    Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, and its morbidity and mortality rates are increasing annually. It is an independent risk factor for intensive care unit-acquired weakness (ICU-AW), which is a common complication of patients in ICU. This situation is also known as sepsis-associated acquired weakness (SAW), and it can be a complication in more than 60% of patients with sepsis. The outcomes of SAW are often prolonged mechanical ventilation, extended hospital stays, and increased morbidity and mortality of patients in ICUs. The pathogenesis of SAW is unclear, and an effective clinical treatment is not available. Ferroptosis is an iron-dependent type of cell death with unique morphological, biochemical, and genetic features. Unlike other forms of cell death such as autophagy, apoptosis, and necrosis, ferroptosis is primarily driven by lipid peroxidation. Cells undergo ferroptosis during sepsis, which further enhances the inflammatory response. This process leads to increased cell death, as well as multi-organ dysfunction and failure. Recently, there have been sporadic reports suggesting that SAW is associated with ferroptosis, but the exact pathophysiological mechanisms remain unclear. Therefore, we reviewed the possible pathogenesis of ferroptosis that leads to SAW and offer new strategies to prevent and treat SAW

    Interaction of Human Serum Album and C60 Aggregates in Solution

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    An important property of C60 in aquatic ecotoxicology is that it can form stable aggregates with nanoscale dimensions, namely nC60. Aggregation allows fullerenes to remain suspended for a long time, and the reactivity of individual C60 is substantially altered in this aggregate form. Herein, we investigated the interaction of nC60 and human serum album (HSA) using the methods of fluorescence, fluorescence dynamics, circular dichroism (CD), and site marker competitive experiments. We proposed a binding model consistent with the available experimental results for the interactions of nC60 with HSA. During the interaction process, the structure and conformation of HSA were affected, leading to functional changes of drug binding sites of HSA

    Region- or state-related differences in expression and activation of extracellular signal-regulated kinases (ERKs) in naĂŻve and pain-experiencing rats

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    <p>Abstract</p> <p>Background</p> <p>Extracellular signal-regulated kinase (ERK), one member of the mitogen-activated protein kinase (MAPK) family, has been suggested to regulate a diverse array of cellular functions, including cell growth, differentiation, survival, as well as neuronal plasticity. Recent evidence indicates a role for ERKs in nociceptive processing in both dorsal root ganglion and spinal cord. However, little literature has been reported to examine the differential distribution and activation of ERK isoforms, ERK1 and ERK2, at different levels of pain-related pathways under both normal and pain states. In the present study, quantitative blot immunolabeling technique was used to determine the spatial and temporal expression of ERK1 and ERK2, as well as their activated forms, in the spinal cord, primary somatosensory cortex (SI area of cortex), and hippocampus under normal, transient pain and persistent pain states.</p> <p>Results</p> <p>In naĂŻve rats, we detected regional differences in total expression of ERK1 and ERK2 across different areas. In the spinal cord, ERK1 was expressed more abundantly than ERK2, while in the SI area of cortex and hippocampus, there was a larger amount of ERK2 than ERK1. Moreover, phosphorylated ERK2 (pERK2), not phosphorylated ERK1 (pERK1), was normally expressed with a high level in the SI area and hippocampus, but both pERK1 and pERK2 were barely detectable in normal spinal cord. Intraplantar saline or bee venom injection, mimicking transient or persistent pain respectively, can equally initiate an intense and long-lasting activation of ERKs in all three areas examined. However, isoform-dependent differences existed among these areas, that is, pERK2 exhibited stronger response than pERK1 in the spinal cord, whereas ERK1 was more remarkably activated than ERK2 in the S1 area and hippocampus.</p> <p>Conclusion</p> <p>Taken these results together, we conclude that: (1) under normal state, while ERK immunoreactivity is broadly distributed in the rat central nervous system in general, the relative abundance of ERK1 and ERK2 differs greatly among specific regions; (2) under pain state, either ERK1 or ERK2 can be effectively phosphorylated with a long-term duration by both transient and persistent pain, but their response patterns differ from each other across distinct regions; (3) The long-lasting ERKs activation induced by bee venom injection is highly correlated with our previous behavioral, electrophysiological, morphological and pharmacological observations, lending further support to the functional importance of ERKs-mediated signaling pathways in the processing of negative consequences of pain associated with sensory, emotional and cognitive dimensions.</p

    Chemisorption-induced formation of biphenylene dimer on Ag(111)

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    We report an example that demonstrates the clear interdependence between surface-supported reactions and molecular-adsorption configurations. Two biphenyl-based molecules with two and four bromine substituents, i.e., 2,2′-dibromobiphenyl (DBBP) and 2,2′,6,6′-tetrabromo-1,1′-biphenyl (TBBP), show completely different reaction pathways on a Ag(111) surface, leading to the selective formation of dibenzo[e,l]pyrene and biphenylene dimer, respectively. By combining low-temperature scanning tunneling microscopy, synchrotron radiation photoemission spectroscopy, and density functional theory calculations, we unravel the underlying reaction mechanism. After debromination, a biradical biphenyl can be stabilized by surface Ag adatoms, while a four-radical biphenyl undergoes spontaneous intramolecular annulation due to its extreme instability on Ag(111). Such different chemisorption-induced precursor states between DBBP and TBBP consequently lead to different reaction pathways after further annealing. In addition, using bond-resolving scanning tunneling microscopy and scanning tunneling spectroscopy, we determine with atomic precision the bond-length alternation of the biphenylene dimer product, which contains 4-, 6-, and 8-membered rings. The 4-membered ring units turn out to be radialene structures.This work was financially supported by the National Natural Science Foundation of China (21773222, 51772285, 21872131, U1732272, and U1932214), the National Key R&D Program of China (2017YFA0403402, 2017YFA0403403, and 2019YFA0405601), and Users with Excellence Program of Hefei Science Center CAS (2020HSC-UE004). The work at Washington State University was primarily funded through the National Science Foundation CAREER program under Contract no. CBET-1653561. This work was also partially funded by the Joint Center for Deployment and Research in Earth Abundant Materials (JCDREAM) in Washington State. Most of the computational resources were provided by the Kamiak HPC under the Center for Institutional Research Computing at Washington State University. This research also used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract no. DE-AC02-05CH11231. The work at Donostia International Physics Center was primarily funded through the Juan de la Cierva Grant (no. FJC2019-041202-I) from Spanish Ministry of Economy and Competitiveness, the European Union’s Horizon 2020 Research and Innovation program (Marie Skłodowska-Curie Actions Individual Fellowship (no. 101022150), and the MCIN/AEI/ 10.13039/501100011033 (Grant no. PID2019-107338RB-C63).Peer reviewe

    Mapping Learning in Eigenspace for Harmonious Caricature Generation

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    This paper proposes a mapping learning approach for caricature auto-generation. Simulating the artist’s creativity based on the object’s facial feature, our approach targets discovering what are the principal components of the facial features, and what’s the difference between facial photograph and caricature measured by those components. In training phase, PCA approach is adopted to obtain the principal components. Then, machine learning of SVR (Support Vector Regression) is carried out to learn the mapping model in principal component space. With the mapping model, in application phase, users just need to input a frontal facial photograph for the caricature generation. The caricature is exaggerated based on the original face while reserving essential similar features. Experiments proved comparatively that our approach could generate more harmonious caricatures
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