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A novel stratification scheme combined with internal arteries in CT imaging for guiding postoperative adjuvant transarterial chemoembolization in hepatocellular carcinoma: a retrospective cohort study. Int J Surg 2024; 110:2556-2567. [PMID: 38377071 DOI: 10.1097/js9.0000000000001191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024]
Abstract
BACKGROUND Although postoperative adjuvant transarterial chemoembolization (PA-TACE) improves survival outcomes in a subset of patients with resected hepatocellular carcinoma (HCC), the lack of reliable biomarkers for patient selection remains a significant challenge. The present study aimed to evaluate whether computed tomography imaging can provide more value for predicting benefits from PA-TACE and to establish a new scheme for guiding PA-TACE benefits. METHODS In this retrospective study, patients with HCC who had undergone preoperative contrast-enhanced computed tomography and curative hepatectomy were evaluated. Inverse probability of treatment weight was performed to balance the difference of baseline characteristics. Cox models were used to test the interaction among PA-TACE, imaging features, and pathological indicators. An HCC imaging and pathological classification (HIPC) scheme incorporating these imaging and pathological indicators was established. RESULTS This study included 1488 patients [median age, 52 years (IQR, 45-61 years); 1309 male]. Microvascular invasion (MVI) positive, and diameter >5 cm tumors achieved a higher recurrence-free survival (RFS), and overall survival (OS) benefit, respectively, from PA-TACE than MVI negative, and diameter ≤5 cm tumors. Patients with internal arteries (IA) positive benefited more than those with IA-negative in terms of RFS ( P =0.016) and OS ( P =0.018). PA-TACE achieved significant RFS and OS improvements in HIPC3 (IA present and diameter >5 cm, or two or three tumors) patients but not in HIPC1 (diameter ≤5 cm, MVI negative) and HIPC2 (other single tumor) patients. Our scheme may decrease the number of patients receiving PA-TACE by ~36.5% compared to the previous suggestion. CONCLUSIONS IA can provide more value for predicting the benefit of PA-TACE treatment. The proposed HIPC scheme can be used to stratify patients with and without survival benefits from PA-TACE.
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[Analysis of conventional echocardiographic features in apical hypertrophic cardiomyopathy patients complicated with left ventricular apical aneurysm]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2023; 51:1075-1079. [PMID: 37859360 DOI: 10.3760/cma.j.cn112148-20230815-00079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Objective: To explore the basic characteristics of conventional echocardiography of apical hypertrophic cardiomyopathy (ApHCM) patients complicating with left ventricular apical aneurysm (LVAA). Methods: This is a retrospective study. Patients who underwent echocardiography and cardiac magnetic resonance (CMR) and were diagnosed with ApHCM complicated with LVAA by CMR at Fuwai Hospital, Chinese Academy of Medical Sciences from August 2012 to July 2017 were enrolled. According to whether LVAA was detected by echocardiography, the enrolled patients were divided into two groups: LVAA detected by echocardiography group and LVAA not detected by echocardiography group. Clinical data of the two groups were compared to analyze the causes of missed diagnosis by echocardiography. Results: A total of 21 patients were included, of whom 67.0% (14/21) were males, aged (56.1±16.5) years. Patients with chest discomfort accounted for 81.0% (17/21), palpitation 38.1% (8/21), syncope 14.3% (3/21). ECG showed that 21 (100%) patients had ST-T changes and 18 (85.7%) had deep T-wave invertion. Echocardiography revealed ApHCM in 17 cases (81.0%) and LVAA in 7 cases (33.3%). The mean left ventricular apical aneurysm diameter was 33.0 (18.0, 37.0) mm, and left ventricular ejection fraction was (66.5±6.6) %, and left ventricular apex thickness was (21.0±6.3) mm. Left ventricular outflow tract obstruction was presented in 4 cases and middle left ventricular obstruction in 10 cases. The mean left ventricular apical aneurysm diameter of LVAA detected by echocardiography was greater than that of LVAA not detected by echocardiography (25.0 (18.0, 28.0) mm vs. 16.0 (12.3, 21.0) mm, P=0.006). Conclusions: Conventional echocardiography examination has certain limitations in the diagnosis of ApHCM. Smaller LVAA complicated with ApHCM is likely to be unrecognized by echocardiography. Clinicians should improve their understanding of this disease.
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Deep learning nomogram based on Gd-EOB-DTPA MRI for predicting early recurrence in hepatocellular carcinoma after hepatectomy. Eur Radiol 2023; 33:4949-4961. [PMID: 36786905 PMCID: PMC10289921 DOI: 10.1007/s00330-023-09419-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 12/26/2022] [Accepted: 01/01/2023] [Indexed: 02/15/2023]
Abstract
OBJECTIVES The accurate prediction of post-hepatectomy early recurrence in patients with hepatocellular carcinoma (HCC) is crucial for decision-making regarding postoperative adjuvant treatment and monitoring. We aimed to explore the feasibility of deep learning (DL) features derived from gadoxetate disodium (Gd-EOB-DTPA) MRI, qualitative features, and clinical variables for predicting early recurrence. METHODS In this bicentric study, 285 patients with HCC who underwent Gd-EOB-DTPA MRI before resection were divided into training (n = 195) and validation (n = 90) sets. DL features were extracted from contrast-enhanced MRI images using VGGNet-19. Three feature selection methods and five classification methods were combined for DL signature construction. Subsequently, an mp-MR DL signature fused with multiphase DL signatures of contrast-enhanced images was constructed. Univariate and multivariate logistic regression analyses were used to identify early recurrence risk factors including mp-MR DL signature, microvascular invasion (MVI), and tumor number. A DL nomogram was built by incorporating deep features and significant clinical variables to achieve early recurrence prediction. RESULTS MVI (p = 0.039), tumor number (p = 0.001), and mp-MR DL signature (p < 0.001) were independent risk factors for early recurrence. The DL nomogram outperformed the clinical nomogram in the training set (AUC: 0.949 vs. 0.751; p < 0.001) and validation set (AUC: 0.909 vs. 0.715; p = 0.002). Excellent DL nomogram calibration was achieved in both training and validation sets. Decision curve analysis confirmed the clinical usefulness of DL nomogram. CONCLUSION The proposed DL nomogram was superior to the clinical nomogram in predicting early recurrence for HCC patients after hepatectomy. KEY POINTS • Deep learning signature based on Gd-EOB-DTPA MRI was the predominant independent predictor of early recurrence for hepatocellular carcinoma (HCC) after hepatectomy. • Deep learning nomogram based on clinical factors and Gd-EOB-DTPA MRI features is promising for predicting early recurrence of HCC. • Deep learning nomogram outperformed the conventional clinical nomogram in predicting early recurrence.
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Prediction of knee pain improvement over two years for knee osteoarthritis using a dynamic nomogram based on MRI-derived radiomics: a proof-of-concept study. Osteoarthritis Cartilage 2023; 31:267-278. [PMID: 36334697 DOI: 10.1016/j.joca.2022.10.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 09/26/2022] [Accepted: 10/19/2022] [Indexed: 11/05/2022]
Abstract
OBJECTIVES To develop and validate a nomogram to detect improved knee pain in osteoarthritis (OA) by integrating magnetic resonance imaging (MRI) radiomics signature of subchondral bone and clinical characteristics. METHODS Participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. The primary outcome was 20% improvement of knee pain score over 2 years in participants administrated either vitamin D or placebo. Radiomics features of subchondral bone and clinical characteristics from 216 participants were extracted and analyzed. The participants were randomly split into the training and validation cohorts at a ratio of 8:2. Least absolute shrinkage and selection operator (LASSO) regression was used to select features and generate radiomics signatures. The optimal radiomics signature and clinical indicators were fitted into a nomogram using multivariable logistic regression model. RESULTS The nomogram showed favorable discrimination performance [AUCtraining, 0.79 (95% CI: 0.72-0.79), AUCvalidation, 0.83 (95% CI: 0.70-0.96)] as well as a good calibration. Additional contributing value of fusion radiomics signature to the nomogram was statistically significant (NRI, 0.23; IDI, 0.14, P < 0.001 in training cohort and NRI, 0.29; IDI, 0.18, P < 0.05 in validating cohort). Decision curve analysis confirmed the clinical usefulness of nomogram. CONCLUSION The radiomics-based nomogram comprising the MR radiomics signature and clinical variables achieves a favorable predictive efficacy and accuracy in differentiating improvement in knee pain among OA patients. This proof-of-concept study provides a promising way to predict clinically meaningful outcomes.
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Altered Spontaneous Brain Activity and Functional Integration in Hemodialysis Patients With End-Stage Renal Disease. Front Neurol 2022; 12:801336. [PMID: 35222228 PMCID: PMC8863739 DOI: 10.3389/fneur.2021.801336] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/30/2021] [Indexed: 11/25/2022] Open
Abstract
Purpose Using the amplitude of low-frequency fluctuation (ALFF) and functional connectivity (FC) algorithm to study the alteration of brain function in hemodialysis patients with end-stage renal disease (ESRD). Patients and Methods We recruited 20 patients with ESRD on regular hemodialysis and 17 healthy controls (HCs). All of the participants underwent resting-state fMRI (rs-fMRI), neuropsychological tests, and blood biochemical examination. The individual ALFF values between the two groups were tested by an independent sample t-test. Then, we set the altered ALFF brain areas as seed regions of interest (ROIs), and FC analysis was used to investigate the functional integration patterns between the seed ROI and the voxels within the whole brain. Results The ALFF values of the right precuneus and angular gyrus (RAG) in the ESRD group were lower than those in the HC subjects, but the right precentral gyrus showed higher ALFF values in patients. Hemoglobin (Hb) was negatively correlated with the ALFF values of the right precentral gyrus, and the ALFF values of the right precuneus were negatively correlated with line-tracing test (LTT) scores in patients with ESRD. Patients with ESRD show decreased connectivity between the RAG and the left precuneus, right superior frontal gyrus (RSFG), and the connectivity within the RAG was weak. In addition, FC in the RAG-right cuneus, right precuneus-left supramarginal gyrus was enhanced in the patient group. Conclusion Our research suggested that, in hemodialysis patients with ESRD, the brain areas with abnormal spontaneous brain activity and FC are mainly located in the default mode network (DMN) regions. Hb and the LTT results were correlated with abnormal spontaneous brain activity. These findings provide additional evidence to understand the possible underlying neuropathological mechanisms in patients with ESRD.
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Functional Magnetic Resonance Imaging Study of Thymus Activation Induced by Different Intensity Electrical Stimulation (Journal of Medical Imaging and Health Informatics, Vol. 11(2), pp. 378–385 (2021)). JOURNAL OF MEDICAL IMAGING AND HEALTH INFORMATICS 2022. [DOI: 10.1166/jmihi.2022.3930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Two-Trait Predictor of Venous Invasion on Contrast-Enhanced CT as a Preoperative Predictor of Outcomes for Early-Stage Hepatocellular Carcinoma After Hepatectomy. Front Oncol 2021; 11:688087. [PMID: 34540664 PMCID: PMC8442625 DOI: 10.3389/fonc.2021.688087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/10/2021] [Indexed: 12/24/2022] Open
Abstract
Objectives This study aimed to assess the effectiveness of the two-trait predictor of venous invasion (TTPVI) on contrast-enhanced computed tomography (CECT) for the preoperative prediction of clinical outcomes in patients with early-stage hepatocellular carcinoma (HCC) after hepatectomy. Methods This retrospective study included 280 patients with surgically resected HCC who underwent preoperative CECT between 2012 and 2013. CT imaging features of HCC were assessed, and univariate and multivariate Cox regression analyses were used to evaluate the CT features associated with disease-free survival (DFS) and overall survival (OS). Subgroup analyses were used to summarized the hazard ratios (HRs) between patients in whom TTPVI was present and those in whom TTPVI was absent using a forest plot. Results Capsule appearance [HR, 0.504; 95% confidence interval (CI), 0.341–0.745; p < 0.001], TTPVI (HR, 1.842; 95% CI, 1.319–2.572; p < 0.001) and high level of alanine aminotransferase (HR, 1.620; 95% CI, 1.180–2.225, p = 0.003) were independent risk factors for DFS, and TTPVI (HR, 2.509; 95% CI, 1.518–4.147; p < 0.001), high level of alpha-fetoprotein (HR, 1.722; 95% CI, 1.067–2.788; p = 0.026), and gamma-glutamyl transpeptidase (HR, 1.787; 95% CI, 1.134–2.814; p = 0.026) were independent risk factors for OS. A forest plot revealed that the TTPVI present group had lower DFS and OS rates in most subgroups. Patients in whom TTPVI was present in stages I and II had a lower DFS and OS than those in whom TTPVI was absent. Moreover, there were significant differences in DFS (p < 0.001) and OS (p < 0.001) between patients classified as Barcelona Clinic Liver Cancer stage A in whom TTPVI was absent and in whom TTPVI was present. Conclusions TTPVI may be used as a preoperative biomarker for predicting postoperative outcomes for patients with early-stage HCC.
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A Nomogram Based on CT Deep Learning Signature: A Potential Tool for the Prediction of Overall Survival in Resected Non-Small Cell Lung Cancer Patients. Cancer Manag Res 2021; 13:2897-2906. [PMID: 33833572 PMCID: PMC8019610 DOI: 10.2147/cmar.s299020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/02/2021] [Indexed: 12/29/2022] Open
Abstract
PURPOSE To develop and further validate a deep learning signature-based nomogram from computed tomography (CT) images for prediction of the overall survival (OS) in resected non-small cell lung cancer (NSCLC) patients. PATIENTS AND METHODS A total of 1792 deep learning features were extracted from non-enhanced and venous-phase CT images for each NSCLC patient in training cohort (n=231). Then, a deep learning signature was built with the least absolute shrinkage and selection operator (LASSO) Cox regression model for OS estimation. At last, a nomogram was constructed with the signature and other independent clinical risk factors. The performance of nomogram was assessed by discrimination, calibration and clinical usefulness. In addition, in order to quantify the improvement in performance added by deep learning signature, the net reclassification improvement (NRI) was calculated. The results were validated in external validation cohort (n=77). RESULTS A deep learning signature with 9 selected features was significantly associated with OS in both training cohort (hazard ratio [HR]=5.455, 95% CI: 3.393-8.769, P<0.001) and external validation cohort (HR=3.029, 95% CI: 1.673-5.485, P=0.004). The nomogram combining deep learning signature with clinical risk factors of TNM stage, lymphatic vessel invasion and differentiation grade showed favorable discriminative ability with C-index of 0.800 as well as a good calibration, which was validated in external validation cohort (C-index=0.723). Additional value of deep learning signature to the nomogram was statistically significant (NRI=0.093, P=0.027 for training cohort; NRI=0.106, P=0.040 for validation cohort). Decision curve analysis confirmed the clinical usefulness of this nomogram in predicting OS. CONCLUSION The deep learning signature-based nomogram is a robust tool for prognostic prediction in resected NSCLC patients.
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MRI-based radiomics signature for pretreatment prediction of pathological response to neoadjuvant chemotherapy in osteosarcoma: a multicenter study. Eur Radiol 2021; 31:7913-7924. [PMID: 33825032 DOI: 10.1007/s00330-021-07748-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 12/25/2020] [Accepted: 02/04/2021] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To develop and validate a radiomics signature based on magnetic resonance imaging (MRI) from multicenter datasets for preoperative prediction of pathologic response to neoadjuvant chemotherapy (NAC) in patients with osteosarcoma. METHODS We retrospectively enrolled 102 patients with histologically confirmed osteosarcoma who received chemotherapy before treatment from 4 hospitals (68 in the primary cohort and 34 in the external validation cohort). Quantitative imaging features were extracted from contrast-enhanced fat-suppressed T1-weighted images (CE FS T1WI). Four classification methods, i.e., the least absolute shrinkage and selection operator logistic regression (LASSO-LR), support vector machine (SVM), Gaussian process (GP), and Naive Bayes (NB) algorithm, were compared for feature selection and radiomics signature construction. The predictive performance of the radiomics signatures was assessed with the area under receiver operating characteristics curve (AUC), calibration curve, and decision curve analysis (DCA). RESULTS Thirteen radiomics features selected based on the LASSO-LR classifier were adopted to construct the radiomics signature, which was significantly associated with the pathologic response. The prediction model achieved the best performance between good and poor responders with an AUC of 0.882 (95% CI, 0.837-0.918) in the primary cohort. Calibration curves showed good agreement. Similarly, findings were validated in the external validation cohort with good performance (AUC, 0.842 [95% CI, 0.793-0.883]) and good calibration. DCA analysis confirmed the clinical utility of the selected radiomics signature. CONCLUSION The constructed CE FS T1WI-radiomics signature with excellent performance could provide a potential tool to predict pathologic response to NAC in patients with osteosarcoma. KEY POINTS • The radiomics signature based on multicenter contrast-enhanced MRI was useful to predict response to NAC. • The prediction model obtained with the LASSO-LR classifier achieved the best performance. • The baseline clinical characteristics were not associated with response to NAC.
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Pretreatment Prediction of Relapse Risk in Patients with Osteosarcoma Using Radiomics Nomogram Based on CT: A Retrospective Multicenter Study. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6674471. [PMID: 33614787 PMCID: PMC7878076 DOI: 10.1155/2021/6674471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/22/2020] [Accepted: 01/22/2021] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To develop and externally validate a CT-based radiomics nomogram for pretreatment prediction of relapse in osteosarcoma patients within one year. MATERIALS AND METHODS In this multicenter retrospective study, a total of 80 patients (training cohort: 63 patients from three hospitals; validation cohort: 17 patients from three other hospitals) with osteosarcoma, undergoing pretreatment CT between August 2010 and December 2018, were identified from multicenter databases. Radiomics features were extracted and selected from tumor regions on CT image, and then, the radiomics signature was constructed. The radiomics nomogram that incorporated the radiomics signature and clinical-based risk factors was developed to predict relapse risk with a multivariate Cox regression model using the training cohort and validated using the external validation cohort. The performance of the nomogram was assessed concerning discrimination, calibration, reclassification, and clinical usefulness. RESULTS Kaplan-Meier curves based on the radiomics signature showed a significant difference between the high-risk and the low-risk groups in both training and validation cohorts (P < 0.001 and P = 0.015, respectively). The radiomics nomogram achieved good discriminant results in the training cohort (C-index: 0.779) and the validation cohort (C-index: 0.710) as well as good calibration. Decision curve analysis revealed that the proposed model significantly improved the clinical benefit compared with the clinical-based nomogram (P < 0.001). CONCLUSIONS This multicenter study demonstrates that a radiomics nomogram incorporated the radiomics signature and clinical-based risk factors can increase the predictive value of the osteosarcoma relapse risk, which supports the clinical application in different institutions.
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Functional Magnetic Resonance Imaging Study of Thymus Activation Induced by Different Intensity Electrical Stimulation. JOURNAL OF MEDICAL IMAGING AND HEALTH INFORMATICS 2021. [DOI: 10.1166/jmihi.2021.3297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Functional magnetic resonance imaging (fMRI) was used to observe the activation response of the hypothalamus under different intensity electrical stimulation, and to explore the role of thalamus in the pain regulation network. Ten subjects were selected as normal subjects, and 41 °C
and 51 °C were performed on the dorsal side of the right forearm of all subjects, respectively. CCHS mission-mode functional magnetic resonance (fMRI) scans (41 °C. CCHS-fMRI group and 51 °C CHS-fMRI group) were pre-processed with fMRI using SPM8. A single sample t-test
was used to compare 41 °C CCHS-fMRI group and 51 °C. The CCHS-fMRI group underwent intragroup analysis to observe the activation of brain regions under two different temperature CHS, and recorded the activation intensity of the activation region. A paired t-test was used to
explore the difference in activation between the PD group and the control group, and brain regions with statistically significant differences were analyzed. The activation intensity of the activated brain region was recorded, and the cause of the difference was analyzed. At the end of the
trial, the visual analog scale (CVAS) was used to score the pain experienced by the subject at the stimulation temperature, and then the subject was subjected to a sensory quantification test (QST), including the measurement of thermal sensation (WS) and thermal pain (HP). At the same time,
under the same intensity electrical stimulation, the activation signal of the lateral thalamus was stronger than that of the lateral thalamus, showing a contralateral advantage, while the bilateral thalamus lacked this manifestation. The thalamus should be an important component of the pain-regulating
network. This region exhibits a segregationactivated phenomenon, and each region has its own unique stimulatory response characteristics, which helps to understand the role of the thalamus in the treatment of pain information.
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[Brief summary of echocardiography development]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2020; 48:186-188. [PMID: 32234174 DOI: 10.3760/cma.j.cn112148-20200204-00052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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Multidetector computed tomography in the diagnosis of spontaneous isolated superior mesenteric artery dissection: changes in diameter on nonenhanced scan and stent treatment follow-up. J Int Med Res 2019; 47:6139-6148. [PMID: 31345078 PMCID: PMC7045652 DOI: 10.1177/0300060519860328] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective This study was performed to assess the changes in diameter of the superior mesenteric artery (SMA) in patients with spontaneous isolated SMA dissection (SISMAD) on nonenhanced multidetector computed tomography (MDCT) and determine the clinical value of follow-up MDCT after endovascular stent placement (ESP). Methods The diameters of the SMA and superior mesenteric vein (SMV) as measured on nonenhanced MDCT were compared between 20 patients with SISMAD and 20 control subjects. ESP was performed in 14 patients with SISMAD, and follow-up MDCT was performed after ESP. Results The mean diameter of the SMA in the SISMAD group and control group was 11.69 ± 1.26 and 7.10 ± 0.97 mm, respectively, with a statistically significant difference. The SMA diameters were even larger than the SMV diameters. Follow-up MDCT showed stent patency in 13 patients and occlusion in 1 patient. Conclusions An enlarged diameter of the SMA on nonenhanced MDCT is an important finding for diagnosis of SISMAD, and MDCT is a valuable follow-up method after ESP for SISMAD.
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Differential MicroRNA Expressions in Human Peripheral Blood Mononuclear Cells Are Predictive of Renal Allograft Function. Transplant Proc 2019; 51:715-721. [PMID: 30979455 DOI: 10.1016/j.transproceed.2019.01.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 12/03/2018] [Accepted: 01/17/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND The present diagnostic methods for detecting graft damage after kidney transplantation are either invasive or not available early enough. The microRNAs (miRNAs) in peripheral blood mononuclear cells (PBMCs) have been suggested as promising biomarkers. METHODS Using quantitative real-time polymerase chain reaction, we identified 9 miRNAs (miR-142-5p, miR-142-3p, miR-223, miR-211, miR-486, miR-155, miR-10b, miR-30a, and let-7c) related to the human renal allograft status in PBMCs from 104 kidney transplant recipients. RESULTS The miR-142-5p, miR-142-3p, and miR-223 were significantly upregulated and miR-10b was significantly downregulated in recipients with abnormal levels of serum creatinine 3 to 4 weeks after initial sample collection. Moreover, the miR-142-5p and miR-142-3p were also found to be significantly upregulated in recipients with abnormal levels of cystatin C. Through a combination of the validated miRNAs, receiver operating characteristic analyses yielded the highest area under the curve value of 0.7913 and 0.7063 in predicting the levels of serum creatinine and cystatin C, respectively. In the testing stage, the developed models correctly predicted allograft function in 16 to 17 of 22 recipients (false rate, 22.7%-27.2%). CONCLUSIONS miRNAs in PBMCs of recipients hold great promise to be used as predictive and noninvasive biomarkers after transplantation.
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Comparison of T1 Mapping and T1rho Values with Conventional Diffusion-weighted Imaging to Assess Fibrosis in a Rat Model of Unilateral Ureteral Obstruction. Acad Radiol 2019; 26:22-29. [PMID: 29705280 DOI: 10.1016/j.acra.2018.03.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 03/14/2018] [Accepted: 03/19/2018] [Indexed: 12/14/2022]
Abstract
RATIONALE AND OBJECTIVES The aim of this study was to investigate the potential of magnetic resonance imaging (MRI) T1 mapping and T1 relaxation time in the rotating frame (T1rho) for assessment of renal fibrosis in a rat model of unilateral ureteral obstruction (UUO). MATERIALS AND METHODS UUO was created in 36 rats. Six rats were scanned at each of the six time points (on days 0, 1, 3, 5, 10, and 15 after UUO). The contralateral kidneys were examined as controls. Hematoxylin-eosin, Masson's trichrome, and alpha-smooth muscle actin (α-SMA) antibody staining assays were performed. MRI data obtained with a 3.0T scanner were analyzed with α-SMA expression and Masson's staining. RESULTS The T1 relaxation times and T1rho values increased, and the mean apparent diffusion coefficient (ADC) values decreased with time after UUO. Simple regression analysis indicated that the mean ADCs, T1 relaxation times, and T1rho values had strong correlations with the α-SMA expression levels (R2 = 0.34, R2 = 0.66, R2 = 0.71, respectively; P< .001) and positive Masson's staining (R2 = 0.38, R2 = 0.67, R2 = 0.65, respectively; P< .001). CONCLUSIONS The T1 mapping and T1rho parameters had better correlations with α-SMA expression and Masson's staining than ADC values.
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Evaluation of Placental Perfusion Based on Intravoxel Incoherent Motion Diffusion Weighted Imaging (IVIM-DWI) and Its Predictive Value for Late-Onset Fetal Growth Restriction. Geburtshilfe Frauenheilkd 2018; 79:396-401. [PMID: 31000885 PMCID: PMC6461467 DOI: 10.1055/a-0717-5275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/22/2018] [Accepted: 08/26/2018] [Indexed: 01/21/2023] Open
Abstract
Objective
The aim of this study was to investigate placental blood perfusion in middle and late pregnancy and explore its predictive value for fetal growth restriction (FGR).
Methods
All pregnant women included in the study were examined using placental intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI). Three IVIM parameters (D, f, D*) were obtained for each pregnant woman and analyzed using Image J software. Perfusion fraction f is a radiological marker of placental perfusion. The pulsatility index (PI) of the uterine artery is used to indirectly evaluate placental function.
Results
f-values were significantly lower in the late-onset FGR group compared to the normal late pregnancy group (19.07 vs. 27.78%). In addition, uterine artery PI values were markedly increased in the late-onset FGR group compared to the normal late pregnancy group (1.96 vs. 1.03), and neonatal weight was significantly lower in the late-onset FGR group (2.75 vs. 3.18 kg). There was a significant positive correlation between f-value, uterine artery PI and neonatal weight (r = 0.968, p < 0.01; r = 0.959, p < 0.01). There was a significant negative correlation between f-value and age of gestation (r = − 0.534, p < 0.01).
Conclusion
Perfusion fraction f was strongly correlated with uterine artery blood flow resistance as measured by color Doppler and had a certain predictive value for late-onset FGR.
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Intravoxel Incoherent Motion and Arterial Spin Labeling MRI Analysis of Reversible Unilateral Ureteral Obstruction in Rats. J Magn Reson Imaging 2018; 50:288-296. [PMID: 30328247 DOI: 10.1002/jmri.26536] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 09/20/2018] [Accepted: 09/20/2018] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Renal fibrosis is a common consequence of chronic kidney disease (CKD) and is the mechanism by which various forms of CKD progress to endstage renal failure. Accurate assessment of renal fibrosis is important for treatment. PURPOSE To measure longitudinal changes of intravoxel incoherent motion (IVIM) and arterial spin labeling (ASL) before and after reversible unilateral ureteral obstruction in an animal model. STUDY TYPE Self-controlled animal study. ANIMAL MODEL Surgical obstruction of the ureters was performed and then removed after 5 days. Rats were scanned on Days 0, 1, 3, and 5 after creating the obstruction and on Days 4, 7, and 12 after releasing the obstruction. FIELD STRENGTH/SEQUENCE 3.0T/IVIM/ASL. ASSESSMENT The apparent diffusion coefficient (ADC), pure molecular diffusion (D), perfusion fraction (f), pseudodiffusion (D*), and renal blood flow (RBF) obtained from the ASL were measured. STATISTICAL TESTS Using SPSS v. 20.0 software, P < 0.05 were considered statistically significant. The data from each timepoint were compared using one-way analysis of variance and correlation analysis was applied to various parameters. RESULTS The postobstruction kidneys showed renal tubule swelling and increased collagen fiber content. Renal tubule swelling was relieved after reversing the obstruction, but Masson staining and cell density analysis revealed progressive changes that were primarily localized to the medulla. In general, ADC, D, f, D*, and RBF decreased with time during the 5 days of obstruction, and increased after release of the obstruction. ADC positively correlated with D, f, D*, and RBF (r = 0.415, r = 0.634, r = 0.465 r = 0.586, P < 0.001, respectively) in the cortex in this study. Also, ADC showed a positive correlation with D, f, and D* (r = 0.724, r = 0.749, r = 0.151, P < 0.001, respectively) in the medulla. DATA CONCLUSION Kidney perfusion was the major factor affecting ADC. Functional imaging may be useful for following progression of CKD. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:288-296.
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Using Three-Dimensional Printing to Create Individualized Cranial Nerve Models for Skull Base Tumor Surgery. World Neurosurg 2018; 120:e142-e152. [PMID: 30121411 DOI: 10.1016/j.wneu.2018.07.236] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Using three-dimensional (3D) printing to create individualized patient models of the skull base, the optic chiasm and facial nerve can be previsualized to help identify and protect these structures during tumor removal surgery. METHODS Preoperative imaging data for 2 cases of sellar tumor and 1 case of acoustic neuroma were obtained. Based on these data, the cranial nerves were visualized using 3D T1-weighted turbo field echo sequence and diffusion tensor imaging-based fiber tracking. Mimics software was used to create 3D reconstructions of the skull base regions surrounding the tumors, and 3D solid models were printed for use in simulation of the basic surgical steps. RESULTS The 3D printed personalized skull base tumor solid models contained information regarding the skull, brain tissue, blood vessels, cranial nerves, tumors, and other associated structures. The sphenoid sinus anatomy, saddle area, and cerebellopontine angle region could be visually displayed, and the spatial relationship between the tumor and the cranial nerves and important blood vessels was clearly defined. The models allowed for simulation of the operation, prediction of operative details, and verification of accuracy of cranial nerve reconstruction during the operation. Questionnaire assessment showed that neurosurgeons highly valued the accuracy and usefulness of these skull base tumor models. CONCLUSIONS 3D printed models of skull base tumors and nearby cranial nerves, by allowing for the surgical procedure to be simulated beforehand, facilitate preoperative planning and help prevent cranial nerve injury.
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Staging of rat liver fibrosis using monoexponential, stretched exponential and diffusion kurtosis models with diffusion weighted imaging- magnetic resonance. Oncotarget 2017; 9:2357-2366. [PMID: 29416777 PMCID: PMC5788645 DOI: 10.18632/oncotarget.23413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/05/2017] [Indexed: 12/26/2022] Open
Abstract
Early diagnosis of liver fibrosis is important. The objective of this study was to explore the characteristics and to assess the accuracy of monoexponential, stretched exponential models (SEM), and diffusion kurtosis imaging (DKI) with diffusion-weighted imaging (DWI)-magnetic resonance imaging (MRI) in various stages of liver fibrosis in two standard rat models induced by carbon tetrachloride (CCl4) and biliary duct ligation (BDL). Parameters (ADC, Dapp, Kapp, DDC, α) were measured with a 3.0T MRI. Liver fibrosis stages (F0–F4) were defined by METAVIR scoring. Parameters (ADC, Dapp, DDC) were found to be negatively associated (r: -0.675~-0.789; P<0.05) with advancement of fibrosis stage. The analysis of receiver operating characteristic (ROC) curves illustrated that the areas under the curves (AUC) for ADC, Dapp, and DDC were 0.687~0.957, 0.805~0.938 and 0.876~1.000, respectively. The study showed that (ADC, Dapp, Kapp, DDC, α) from various diffusion models reflected pathological and physiological tissue changes. We conclude that SEM and DKI may provide more accurate information about diffusion, and non-Gaussian diffusion analysis may be a complementary tool for the assessment of liver fibrosis.
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Quantitative Visualization of Dynamic Tracer Transportation in the Extracellular Space of Deep Brain Regions Using Tracer-Based Magnetic Resonance Imaging. Med Sci Monit 2017; 23:4260-4268. [PMID: 28866708 PMCID: PMC5595121 DOI: 10.12659/msm.903010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background This study assessed an innovative tracer-based magnetic resonance imaging (MRI) system to visualize the dynamic transportation of tracers in regions of deep brain extracellular space (ECS) and to measure transportation ability and ECS structure. Material/Methods Gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) was the chosen tracer and was injected into the caudate nucleus and thalamus. Real-time dynamic transportation of Gd-DTPA in ECS was observed and the results were verified by laser scanning confocal microscopy. Using Transwell assay across the blood-brain barrier, a modified diffusion equation was further simplified. Effective diffusion coefficient D* and tortuosity λ were calculated. Immunohistochemical staining and Western blot analysis were used to investigate the extracellular matrix contributing to ECS structure. Results Tracers injected into the caudate nucleus were transported to the ipsilateral frontal and temporal cortices away from the injection points, while both of them injected into the thalamus were only distributed on site. Although the caudate nucleus was closely adjacent to the thalamus, tracer transportation between partitions was not observed. In addition, D* and the λ showed statistically significant differences between partitions. ECS was shown to be a physiologically partitioned system, and its division is characterized by the unique distribution territory and transportation ability of substances located in it. Versican and Tenascin R are possible contributors to the tortuosity of ECS. Conclusions Tracer-based MRI will improve our understanding of the brain microenvironment, improve the techniques for local delivery of drugs, and highlight brain tissue engineering fields in the future.
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Multimodal quantitative magnetic resonance imaging for lumbar intervertebral disc degeneration. Exp Ther Med 2017; 14:2078-2084. [PMID: 28962127 PMCID: PMC5609182 DOI: 10.3892/etm.2017.4786] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 03/17/2017] [Indexed: 01/08/2023] Open
Abstract
The present study investigated the application of the T1ρ and T2 relaxation mapping magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in the evaluation of intervertebral disc degeneration (IDD). A total of 93 asymptomatic subjects were imaged with T1ρ and T2 mapping, as well as DWI. Pfirrmann grading was performed and correlation analysis was conducted for T1ρ, T2 and DWI results with the grading results and age. Pfirrmann grading indicated 69 cases of grade I, 240 cases of grade II, 101 cases of grade III, 43 cases of grade IV and 12 cases of grade V. MRI showed that the T1ρ values of the nucleus pulposi at L4/5 and L5/S1 were significantly reduced (P<0.05) and no significant differences were observed in the T2 values compared with the values of the nucleus pulposus at L1/2, L2/3 and L3/4. The apparent diffusion coefficient (ADC) values of L1/2 were significantly decreased from L2/3 and L3/4 (P<0.05). Correlation analysis revealed that the T1ρ, T, and ADC values were positively correlated with each other. Moreover, the T1ρvalues were significantly decreased with the increase of Pfirrmann grades (P<0.05), with the exception of grades IV and V. However, T2 and ADC values were not significantly different between grades I and II or IV and V. In addition, the T1ρ, T2 and ADC values were significantly decreased with the increase of age in patients with IDD (P<0.05). T1ρ and T2 mapping and DWI are promising techniques for the in vivo diagnosis of IDD, which may be useful in determining the appropriate prevention and treatment options for the disease.
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22
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Measurement of the differential cross sections for top quark pair production as a function of kinematic event variables in ppcollisions at s=7and 8 TeV. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.94.052006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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23
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Measurement of the [Formula: see text] cross section in pp collisions at [Formula: see text] TeVand limits on anomalous gauge couplings. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:401. [PMID: 28286414 PMCID: PMC5324601 DOI: 10.1140/epjc/s10052-016-4219-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 06/22/2016] [Indexed: 06/06/2023]
Abstract
A measurement of the W boson pair production cross section in proton-proton collisions at [Formula: see text] TeV is presented. The data collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4[Formula: see text]. The [Formula: see text] candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured [Formula: see text] cross section is [Formula: see text], consistent with the standard model prediction. The [Formula: see text] cross sections are also measured in two different fiducial phase space regions. The normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. The corresponding 95 % confidence level intervals are [Formula: see text], [Formula: see text], [Formula: see text], in the HISZ basis.
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Grants
- Austrian Federal Ministry of Science, Research and Economy
- Austrian Science Fund
- Belgian Fonds de la Recherche Scientifique
- Belgian Fonds voor Wetenschappelijk Onderzoek
- CNPq
- CAPES
- FAPERJ
- FAPESP
- Bulgarian Ministry of Education and Science
- CERN
- Chinese Academy of Sciences
- Ministry of Science and Technology
- Chinese National Natural Science Foundation of China
- Colombian Funding Agency (COLCIENCIAS)
- Croatian Ministry of Science, Education and Sport
- Croatian Science Foundation
- Research Promotion Foundation
- Ministry of Education and Research
- Estonian Research Council via IUT23-4 and IUT23-6
- European Regional Development Fund
- Academy of Finland
- Finnish Ministry of Education and Culture
- Helsinki Institute of Physics
- Institut National de Physique Nucléaire et de Physique des Particules
- Centre National de la Recherche Scientifique
- Commissariat à l’Énergie Atomique et aux Énergies Alternatives
- Bundesministerium für Bildung und Forschung
- Deutsche Forschungsgemeinschaft
- Helmholtz-Gemeinschaft Deutscher Forschungszentren
- General Secretariat for Research and Technology
- National Scientific Research Foundation
- National Innovation Office
- Department of Atomic Energy
- Department of Science and Technology
- Institute for Research in Fundamental Studies
- Science Foundation
- Istituto Nazionale di Fisica Nucleare
- Korean Ministry of Education, Science and Technology
- National Research Foundation of Korea (NRF)
- Lithuanian Academy of Sciences
- Ministry of Education
- University of Malaya
- BUAP
- CINVESTAV
- CONACYT
- LNS
- SEP
- UASLP
- Ministry of Business, Innovation and Employment
- Pakistan Atomic Energy Commission
- Ministry of Science and Higher Education
- National Science Centre
- Fundação para a Ciência e a Tecnologia
- JINR, Dubna
- Ministry of Education and Science of the Russian Federation
- Federal Agency of Atomic Energy of the Russian Federation
- Russian Academy of Sciences
- Russian Foundation for Basic Research
- Ministry of Education, Science and Technological Development of Serbia
- Secretaría de Estado de Investigación, Desarrollo e Innovación
- Programa Consolider-Ingenio 2010
- ETH Board
- ETH Zurich
- PSI
- SNF
- UniZH
- Canton Zurich
- SER
- Thailand Center of Excellence in Physics
- Institute for the Promotion of Teaching Science and Technology of Thailand
- Special Task Force for Activating Research
- National Science and Technology Development Agency of Thailand
- Scientific and Technical Research Council of Turkey
- Turkish Atomic Energy Authority
- National Academy of Sciences of Ukraine
- State Fund for Fundamental Researches
- Science and Technology Facilities Council
- US Department of Energy
- US National Science Foundation
- Marie-Curie programme
- European Research Council and EPLANET (European Union)
- Leventis Foundation
- Alfred P. Sloan Foundation
- Alexander von Humboldt Foundation
- Belgian Federal Science Policy Office
- Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium)
- Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)
- Ministry of Education, Youth and Sports (MEYS) of the Czech Republic
- Council of Science and Industrial Research, India
- HOMING PLUS programme of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund
- OPUS programme of the National Science Center
- Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF
- National Priorities Research Program by Qatar National Research Fund
- Programa Clarín-COFUND del Principado de Asturias
- Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand)
- CUAASC
- Welch Foundation, contract C-1845
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Forward-backward asymmetry of Drell-Yan lepton pairs in pp collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:325. [PMID: 28280439 PMCID: PMC5321276 DOI: 10.1140/epjc/s10052-016-4156-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/22/2016] [Indexed: 06/06/2023]
Abstract
A measurement of the forward-backward asymmetry [Formula: see text] of oppositely charged lepton pairs ([Formula: see text] and [Formula: see text]) produced via [Formula: see text] boson exchange in pp collisions at [Formula: see text] [Formula: see text] is presented. The data sample corresponds to an integrated luminosity of 19.7[Formula: see text] collected with the CMS detector at the LHC. The measurement of [Formula: see text] is performed for dilepton masses between 40[Formula: see text] and 2[Formula: see text] and for dilepton rapidity up to 5. The [Formula: see text] measurements as a function of dilepton mass and rapidity are compared with the standard model predictions.
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Grants
- Austrian Federal Ministry of Science, Research and Economy
- Austrian Science Fund
- Belgian Fonds de la Recherche Scientifique
- Belgian Fonds voor Wetenschappelijk Onderzoek
- CNPq
- CAPES
- FAPERJ
- FAPESP
- Bulgarian Ministry of Education and Science
- Chinese Academy of Sciences
- Ministry of Science and Technology
- Chinese National Natural Science Foundation of China
- Colombian Funding Agency (COLCIENCIAS)
- Croatian Ministry of Science, Education and Sport
- Croatian Science Foundation
- Research Promotion Foundation
- Ministry of Education and Research, Estonian Research Council via IUT23-4 and IUT23-6
- European Regional Development Fund
- Academy of Finland
- Finnish Ministry of Education and Culture
- Helsinki Institute of Physics
- Institut National de Physique NuclTaire et de Physiqe des Particules/CNRS
- Commissariat a l’+nergie Atomique et aux +nergies Alternatives / CEA
- Bundesministerium fnr Bildung und Forschung
- Deutsche Forschungsgemeinschaft
- Helmholtz-Gemeinschaft Deutscher Forschungszentren
- General Secretariat for Research and Technology
- National Scientific Research Foundation
- National Innovation Office
- Department of Atomic Energy
- Department of Science and Technology
- Institute for Studies in Theoretical Physics and Mathematics
- Science Foundation
- Istituto Nazionale di Fisica Nucleare
- Korean Ministry of Education, Science and Technology
- National Research Foundation of Korea (NRF)
- Lithuanian Academy of Sciences
- Ministry of Education
- University of Malayam
- CINVESTAV
- CONACYT
- SEP
- UASLP
- Ministry of Business, Innovation and Employment
- Pakistan Atomic Energy Commission
- Ministry of Science and Higher Education
- National Science Centre
- Fundatpo para a CiOncia e a Tecnologia
- JINR, Dubna
- Ministry of Education and Science of the Russian Federation
- Federal Agency of Atomic Energy of the Russian Federation
- Russian Academy of Sciences
- Russian Foundation for Basic Research
- Ministry of Education, Science and Technological Development of Serbia
- Secretarfa de Estado de Investigaci=n, Desarrollo e Innovaci=n
- Programa Consolider-Ingenio 2010
- ETH Board
- ETH Zurich
- PSI
- SNF
- UniZH
- Canton Zurich
- SER
- Thailand Center of Excellence in Physics
- Institute for the Promotion of Teaching Science and Technology of Thailand
- Special Task Force for Activating Research
- National Science and Technology Development Agency of Thailand
- Scientific and Technical Research Council of Turkey
- Turkish Atomic Energy Authority
- National Academy of Sciences of Ukraine
- State Fund for Fundamental Researches
- Science and Technology Facilities Council
- US Department of Energy
- US National Science Foundation
- Marie-Curie programme
- European Research Council and EPLANET (European Union)
- Leventis Foundation
- Alfred P. Sloan Foundation
- Alexander von Humboldt Foundation
- Belgian Federal Science Policy Office
- Fonds pour la Formation a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium)
- Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)
- Ministry of Education, Youth and Sports (MEYS) of the Czech Republic
- Council of Science and Industrial Research, India
- HOMING PLUS programme of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund
- Compagnia di San Paolo (Torino)
- Consorzio per la Fisica (Trieste)
- MIUR project 20108T4XTM (Italy)
- Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF
- National Priorities Research Program by Qatar National Research Fund
- Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand)
- Welch Foundation
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Ecological speciation in sympatric palms: 1. Gene expression, selection and pleiotropy. J Evol Biol 2016; 29:1472-87. [PMID: 27177130 PMCID: PMC6680112 DOI: 10.1111/jeb.12895] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 05/04/2016] [Accepted: 05/11/2016] [Indexed: 02/02/2023]
Abstract
Ecological speciation requires divergent selection, reproductive isolation and a genetic mechanism to link the two. We examined the role of gene expression and coding sequence evolution in this process using two species of Howea palms that have diverged sympatrically on Lord Howe Island, Australia. These palms are associated with distinct soil types and have displaced flowering times, representing an ideal candidate for ecological speciation. We generated large amounts of RNA‐Seq data from multiple individuals and tissue types collected on the island from each of the two species. We found that differentially expressed loci as well as those with divergent coding sequences between Howea species were associated with known ecological and phenotypic differences, including response to salinity, drought, pH and flowering time. From these loci, we identified potential ‘ecological speciation genes’ and further validate their effect on flowering time by knocking out orthologous loci in a model plant species. Finally, we put forward six plausible ecological speciation loci, providing support for the hypothesis that pleiotropy could help to overcome the antagonism between selection and recombination during speciation with gene flow.
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Measurement of the [Formula: see text] production cross section in the all-jets final state in pp collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:128. [PMID: 27471431 PMCID: PMC4946853 DOI: 10.1140/epjc/s10052-016-3956-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 02/18/2016] [Indexed: 06/06/2023]
Abstract
The cross section for [Formula: see text] production in the all-jets final state is measured in pp collisions at a centre-of-mass energy of 8 [Formula: see text] at the LHC with the CMS detector, in data corresponding to an integrated luminosity of 18.4 [Formula: see text]. The inclusive cross section is found to be [Formula: see text] [Formula: see text]. The normalized differential cross sections are measured as a function of the top quark transverse momenta, [Formula: see text], and compared to predictions from quantum chromodynamics. The results are reported at detector, parton, and particle levels. In all cases, the measured top quark [Formula: see text] spectra are significantly softer than theoretical predictions.
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Measurement of the charge asymmetry in top quark pair production inppcollisions ats=8 TeVusing a template method. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.93.034014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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Experimentation and numerical modeling of cyclic voltammetry for electrochemical micro-sized sensors under the influence of electrolyte flow. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2015.12.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Study of B Meson Production in p+Pb Collisions at √[S(NN)]=5.02 TeV Using Exclusive Hadronic Decays. PHYSICAL REVIEW LETTERS 2016; 116:032301. [PMID: 26849587 DOI: 10.1103/physrevlett.116.032301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Indexed: 06/05/2023]
Abstract
The production cross sections of the B^{+}, B^{0}, and B_{s}^{0} mesons, and of their charge conjugates, are measured via exclusive hadronic decays in p+Pb collisions at the center-of-mass energy sqrt[s_{NN}]=5.02 TeV with the CMS detector at the CERN LHC. The data set used for this analysis corresponds to an integrated luminosity of 34.6 nb^{-1}. The production cross sections are measured in the transverse momentum range between 10 and 60 GeV/c. No significant modification is observed compared to proton-proton perturbative QCD calculations scaled by the number of incoherent nucleon-nucleon collisions. These results provide a baseline for the study of in-medium b quark energy loss in Pb+Pb collisions.
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Measurement of differential cross sections for Higgs boson production in the diphoton decay channel in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2016; 76:13. [PMID: 26855607 PMCID: PMC4732665 DOI: 10.1140/epjc/s10052-015-3853-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 12/15/2015] [Indexed: 06/05/2023]
Abstract
A measurement is presented of differential cross sections for Higgs boson (H) production in pp collisions at [Formula: see text][Formula: see text]. The analysis exploits the [Formula: see text] decay in data corresponding to an integrated luminosity of 19.7[Formula: see text] collected by the CMS experiment at the LHC. The cross section is measured as a function of the kinematic properties of the diphoton system and of the associated jets. Results corrected for detector effects are compared with predictions at next-to-leading order and next-to-next-to-leading order in perturbative quantum chromodynamics, as well as with predictions beyond the standard model. For isolated photons with pseudorapidities [Formula: see text], and with the photon of largest and next-to-largest transverse momentum ([Formula: see text]) divided by the diphoton mass [Formula: see text] satisfying the respective conditions of [Formula: see text] and [Formula: see text], the total fiducial cross section is [Formula: see text][Formula: see text].
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Decoration of Si-nanowires-grafted Si micropillar array with Ag nanoparticles for photoelectrocatalytic dechlorination of 4-chlorophenol. RSC Adv 2016. [DOI: 10.1039/c6ra12360k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The energetic photoelectrochemical performance of an Ag nanoparticle-decorated Si-nanowire-grafted Si micropillar array and its capability in the control of halogenated pollutants are reported.
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Measurement of the differential cross section for top quark pair production in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:542. [PMID: 26640401 PMCID: PMC4657759 DOI: 10.1140/epjc/s10052-015-3709-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 09/29/2015] [Indexed: 05/22/2023]
Abstract
The normalized differential cross section for top quark pair ([Formula: see text]) production is measured in pp collisions at a centre-of-mass energy of 8[Formula: see text] at the CERN LHC using the CMS detector in data corresponding to an integrated luminosity of 19.7[Formula: see text]. The measurements are performed in the lepton[Formula: see text]jets ([Formula: see text][Formula: see text]jets) and in the dilepton ([Formula: see text], [Formula: see text], and [Formula: see text]) decay channels. The [Formula: see text] cross section is measured as a function of the kinematic properties of the charged leptons, the jets associated to b quarks, the top quarks, and the [Formula: see text] system. The data are compared with several predictions from perturbative quantum chromodynamic up to approximate next-to-next-to-leading-order precision. No significant deviations are observed relative to the standard model predictions.
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Palmitate induces ER calcium depletion and apoptosis in mouse podocytes subsequent to mitochondrial oxidative stress. Cell Death Dis 2015; 6:e1976. [PMID: 26583319 PMCID: PMC4670935 DOI: 10.1038/cddis.2015.331] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 10/02/2015] [Accepted: 10/12/2015] [Indexed: 12/14/2022]
Abstract
Pathologic alterations in podocytes lead to failure of an essential component of the glomerular filtration barrier and proteinuria in chronic kidney diseases. Elevated levels of saturated free fatty acid (FFA) are harmful to various tissues, implemented in the progression of diabetes and its complications such as proteinuria in diabetic nephropathy. Here, we investigated the molecular mechanism of palmitate cytotoxicity in cultured mouse podocytes. Incubation with palmitate dose-dependently increased cytosolic and mitochondrial reactive oxygen species, depolarized the mitochondrial membrane potential, impaired ATP synthesis and elicited apoptotic cell death. Palmitate not only evoked mitochondrial fragmentation but also caused marked dilation of the endoplasmic reticulum (ER). Consistently, palmitate upregulated ER stress proteins, oligomerized stromal interaction molecule 1 (STIM1) in the subplasmalemmal ER membrane, abolished the cyclopiazonic acid-induced cytosolic Ca2+ increase due to depletion of luminal ER Ca2+. Palmitate-induced ER Ca2+ depletion and cytotoxicity were blocked by a selective inhibitor of the fatty-acid transporter FAT/CD36. Loss of the ER Ca2+ pool induced by palmitate was reverted by the phospholipase C (PLC) inhibitor edelfosine. Palmitate-dependent activation of PLC was further demonstrated by following cytosolic translocation of the pleckstrin homology domain of PLC in palmitate-treated podocytes. An inhibitor of diacylglycerol (DAG) kinase, which elevates cytosolic DAG, strongly promoted ER Ca2+ depletion by low-dose palmitate. GF109203X, a PKC inhibitor, partially prevented palmitate-induced ER Ca2+ loss. Remarkably, the mitochondrial antioxidant mitoTEMPO inhibited palmitate-induced PLC activation, ER Ca2+ depletion and cytotoxicity. Palmitate elicited cytoskeletal changes in podocytes and increased albumin permeability, which was also blocked by mitoTEMPO. These data suggest that oxidative stress caused by saturated FFA leads to mitochondrial dysfunction and ER Ca2+ depletion through FAT/CD36 and PLC signaling, possibly contributing to podocyte injury.
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Measurements of the [Formula: see text][Formula: see text] production cross sections in the [Formula: see text] channel in proton-proton collisions at [Formula: see text] and [Formula: see text] and combined constraints on triple gauge couplings. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:511. [PMID: 26549982 PMCID: PMC4627252 DOI: 10.1140/epjc/s10052-015-3706-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 09/25/2015] [Indexed: 06/05/2023]
Abstract
Measurements of the [Formula: see text][Formula: see text] production cross sections in proton-proton collisions at center-of-mass energies of 7 and 8[Formula: see text] are presented. Candidate events for the leptonic decay mode [Formula: see text], where [Formula: see text] denotes an electron or a muon, are reconstructed and selected from data corresponding to an integrated luminosity of 5.1 (19.6)[Formula: see text] at 7 (8)[Formula: see text] collected with the CMS experiment. The measured cross sections, [Formula: see text] at 7[Formula: see text], and [Formula: see text] at 8[Formula: see text], are in good agreement with the standard model predictions with next-to-leading-order accuracy. The selected data are analyzed to search for anomalous triple gauge couplings involving the [Formula: see text][Formula: see text] final state. In the absence of any deviation from the standard model predictions, limits are set on the relevant parameters. These limits are then combined with the previously published CMS results for [Formula: see text][Formula: see text] in 4[Formula: see text] final states, yielding the most stringent constraints on the anomalous couplings.
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Assessment of liver fibrosis in rats by MRI with apparent diffusion coefficient and T1 relaxation time in the rotating frame. J Magn Reson Imaging 2015; 43:1082-9. [PMID: 26497954 DOI: 10.1002/jmri.25084] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/14/2015] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To explore the value of T1 relaxation times in the rotating frame (T1 ρ or T1 rho) for evaluating liver fibrosis stage, compared to apparent diffusion coefficients (ADCs). MATERIALS AND METHODS Liver fibrosis in model rats (n = 50) was produced by carbon tetrachloride (CCl4 ) injection. Five rats died during the experiment. Surviving model rats (n = 45) and controls (n = 15) were subjected to 3.0T MRI and the ADCs (b-values: 0, 800 s/mm(2) ) and T1 ρ values were determined. Liver fibrosis stage (F0-F4) was defined based on METAVIR scoring. Nonparametric statistical methods and receiver operating characteristic (ROC) curve analyses were employed to determine diagnostic accuracy. RESULTS Mean ADC and T1 ρ associated negatively (r = -0.732 P < 0.001) and positively (r = 0.863 P < 0.001), respectively, with severity of fibrosis stage. Analysis of ROC curves for fibrosis staging showed that the area under the curve (AUC) for T1 ρ (stage F0 vs. F1-F4 = 0.976, stage F0-F1 vs. F2-F4 = 0.920, stage F0-F2 vs. F3-F4 = 0.938, and stage F0-F3 vs. F4 = 0.931) was larger than that for ADCs (0.917, 0.924, 0.842, and 0.781, respectively). CONCLUSION ADC and T1 ρ values correlate with liver fibrosis stage. The performance of the T1 ρ parameter was superior to that of the ADC parameter in the differentiation of liver fibrosis stages in a CCl4 rat model.
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Constraints on the pMSSM, AMSB model and on other models from the search for long-lived charged particles in proton-proton collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:325. [PMID: 26213486 PMCID: PMC4509674 DOI: 10.1140/epjc/s10052-015-3533-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 06/19/2015] [Indexed: 06/10/2023]
Abstract
Stringent limits are set on the long-lived lepton-like sector of the phenomenological minimal supersymmetric standard model (pMSSM) and the anomaly-mediated supersymmetry breaking (AMSB) model. The limits are derived from the results presented in a recent search for long-lived charged particles in proton-proton collisions, based on data collected by the CMS detector at a centre-of-mass energy of 8 TeV at the Large Hadron Collider. In the pMSSM parameter sub-space considered, 95.9 % of the points predicting charginos with a lifetime of at least 10 ns are excluded. These constraints on the pMSSM are the first obtained at the LHC. Charginos with a lifetime greater than 100 ns and masses up to about 800 GeV in the AMSB model are also excluded. The method described can also be used to set constraints on other models.
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Evidence for Collective Multiparticle Correlations in p-Pb Collisions. PHYSICAL REVIEW LETTERS 2015; 115:012301. [PMID: 26182092 DOI: 10.1103/physrevlett.115.012301] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Indexed: 06/04/2023]
Abstract
The second-order azimuthal anisotropy Fourier harmonics, v2, are obtained in p-Pb and PbPb collisions over a wide pseudorapidity (η) range based on correlations among six or more charged particles. The p-Pb data, corresponding to an integrated luminosity of 35 nb-1, were collected during the 2013 LHC p-Pb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. A sample of semiperipheral PbPb collision data at √sNN=2.76 TeV, corresponding to an integrated luminosity of 2.5 μb-1 and covering a similar range of particle multiplicities as the p-Pb data, is also analyzed for comparison. The six- and eight-particle cumulant and the Lee-Yang zeros methods are used to extract the v2 coefficients, extending previous studies of two- and four-particle correlations. For both the p-Pb and PbPb systems, the v2 values obtained with correlations among more than four particles are consistent with previously published four-particle results. These data support the interpretation of a collective origin for the previously observed long-range (large Δη) correlations in both systems. The ratios of v2 values corresponding to correlations including different numbers of particles are compared to theoretical predictions that assume a hydrodynamic behavior of a p-Pb system dominated by fluctuations in the positions of participant nucleons. These results provide new insights into the multiparticle dynamics of collision systems with a very small overlapping region.
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Distributions of topological observables in inclusive three- and four-jet events in pp collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:302. [PMID: 26190937 PMCID: PMC4498646 DOI: 10.1140/epjc/s10052-015-3491-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 06/02/2015] [Indexed: 06/04/2023]
Abstract
This paper presents distributions of topological observables in inclusive three- and four-jet events produced in pp collisions at a centre-of-mass energy of 7[Formula: see text] with a data sample collected by the CMS experiment corresponding to a luminosity of 5.1[Formula: see text]. The distributions are corrected for detector effects, and compared with several event generators based on two- and multi-parton matrix elements at leading order. Among the considered calculations, MadGraph interfaced with pythia6 displays the overall best agreement with data.
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Constraints on parton distribution functions and extraction of the strong coupling constant from the inclusive jet cross section in pp collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:288. [PMID: 26146483 PMCID: PMC4482490 DOI: 10.1140/epjc/s10052-015-3499-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 06/02/2015] [Indexed: 06/01/2023]
Abstract
The inclusive jet cross section for proton-proton collisions at a centre-of-mass energy of 7[Formula: see text] was measured by the CMS Collaboration at the LHC with data corresponding to an integrated luminosity of 5.0[Formula: see text]. The measurement covers a phase space up to 2[Formula: see text] in jet transverse momentum and 2.5 in absolute jet rapidity. The statistical precision of these data leads to stringent constraints on the parton distribution functions of the proton. The data provide important input for the gluon density at high fractions of the proton momentum and for the strong coupling constant at large energy scales. Using predictions from perturbative quantum chromodynamics at next-to-leading order, complemented with electroweak corrections, the constraining power of these data is investigated and the strong coupling constant at the Z boson mass [Formula: see text] is determined to be [Formula: see text], which is in agreement with the world average.
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Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:251. [PMID: 26097407 PMCID: PMC4464697 DOI: 10.1140/epjc/s10052-015-3454-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/11/2015] [Indexed: 05/28/2023]
Abstract
A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5[Formula: see text] collected by the CMS experiment at the LHC in [Formula: see text] collisions at a centre-of-mass energy of 8[Formula: see text]. In order to separate the signal from the larger [Formula: see text] + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, [Formula: see text], relative to the standard model prediction for a Higgs boson mass of 125[Formula: see text]. The observed (expected) exclusion limit at a 95 % confidence level is [Formula: see text] (3.3), corresponding to a best fit value [Formula: see text].
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Search for dark matter, extra dimensions, and unparticles in monojet events in proton-proton collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:235. [PMID: 26069461 PMCID: PMC4455910 DOI: 10.1140/epjc/s10052-015-3451-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 05/11/2015] [Indexed: 06/02/2023]
Abstract
Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in proton-proton collisions at the LHC and correspond to an integrated luminosity of 19.7[Formula: see text]at a centre-of-mass energy of 8[Formula: see text]. The number of observed events is found to be consistent with the standard model prediction. Limits are placed on the DM-nucleon scattering cross section as a function of the DM particle mass for spin-dependent and spin-independent interactions. Limits are also placed on the scale parameter [Formula: see text] in the Arkani-Hamed, Dimopoulos, and Dvali (ADD) model of large extra dimensions, and on the unparticle model parameter [Formula: see text]. The constraints on ADD models and unparticles are the most stringent limits in this channel and those on the DM-nucleon scattering cross section are an improvement over previous collider results.
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Nuclear effects on the transverse momentum spectra of charged particles in pPb collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:237. [PMID: 26069462 PMCID: PMC4455909 DOI: 10.1140/epjc/s10052-015-3435-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/01/2015] [Indexed: 06/04/2023]
Abstract
Transverse momentum spectra of charged particles are measured by the CMS experiment at the CERN LHC in pPb collisions at [Formula: see text][Formula: see text], in the range [Formula: see text][Formula: see text] and pseudorapidity [Formula: see text] in the proton-nucleon center-of-mass frame. For [Formula: see text][Formula: see text], the charged-particle production is asymmetric about [Formula: see text], with smaller yield observed in the direction of the proton beam, qualitatively consistent with expectations from shadowing in nuclear parton distribution functions (nPDF). A pp reference spectrum at [Formula: see text][Formula: see text] is obtained by interpolation from previous measurements at higher and lower center-of-mass energies. The [Formula: see text] distribution measured in pPb collisions shows an enhancement of charged particles with [Formula: see text][Formula: see text] compared to expectations from the pp reference. The enhancement is larger than predicted by perturbative quantum chromodynamics calculations that include antishadowing modifications of nPDFs.
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Measurement of J/ψ and ψ(2S) Prompt Double-Differential Cross Sections in pp Collisions at sqrt[s]=7 TeV. PHYSICAL REVIEW LETTERS 2015; 114:191802. [PMID: 26024161 DOI: 10.1103/physrevlett.114.191802] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Indexed: 06/04/2023]
Abstract
The double-differential cross sections of promptly produced J/ψ and ψ(2S) mesons are measured in pp collisions at sqrt[s]=7 TeV, as a function of transverse momentum p_{T} and absolute rapidity |y|. The analysis uses J/ψ and ψ(2S) dimuon samples collected by the CMS experiment, corresponding to integrated luminosities of 4.55 and 4.90 fb^{-1}, respectively. The results are based on a two-dimensional analysis of the dimuon invariant mass and decay length, and extend to p_{T}=120 and 100 GeV for the J/ψ and ψ(2S), respectively, when integrated over the interval |y|<1.2. The ratio of the ψ(2S) to J/ψ cross sections is also reported for |y|<1.2, over the range 10<p_{T}<100 GeV. These are the highest p_{T} values for which the cross sections and ratio have been measured.
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Precise determination of the mass of the Higgs boson and tests of compatibility of its couplings with the standard model predictions using proton collisions at 7 and 8[Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:212. [PMID: 25999783 PMCID: PMC4433454 DOI: 10.1140/epjc/s10052-015-3351-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 03/09/2015] [Indexed: 05/28/2023]
Abstract
Properties of the Higgs boson with mass near 125[Formula: see text] are measured in proton-proton collisions with the CMS experiment at the LHC. Comprehensive sets of production and decay measurements are combined. The decay channels include [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] pairs. The data samples were collected in 2011 and 2012 and correspond to integrated luminosities of up to 5.1[Formula: see text] at 7[Formula: see text] and up to 19.7[Formula: see text] at 8[Formula: see text]. From the high-resolution [Formula: see text] and [Formula: see text] channels, the mass of the Higgs boson is determined to be [Formula: see text]. For this mass value, the event yields obtained in the different analyses tagging specific decay channels and production mechanisms are consistent with those expected for the standard model Higgs boson. The combined best-fit signal relative to the standard model expectation is [Formula: see text] at the measured mass. The couplings of the Higgs boson are probed for deviations in magnitude from the standard model predictions in multiple ways, including searches for invisible and undetected decays. No significant deviations are found.
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Measurement of the inclusive 3-jet production differential cross section in proton-proton collisions at 7 TeV and determination of the strong coupling constant in the TeV range. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:186. [PMID: 25983654 PMCID: PMC4423910 DOI: 10.1140/epjc/s10052-015-3376-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/27/2015] [Indexed: 06/04/2023]
Abstract
This paper presents a measurement of the inclusive 3-jet production differential cross section at a proton-proton centre-of-mass energy of 7 TeV using data corresponding to an integrated luminosity of 5[Formula: see text]collected with the CMS detector. The analysis is based on the three jets with the highest transverse momenta. The cross section is measured as a function of the invariant mass of the three jets in a range of 445-3270 GeV and in two bins of the maximum rapidity of the jets up to a value of 2. A comparison between the measurement and the prediction from perturbative QCD at next-to-leading order is performed. Within uncertainties, data and theory are in agreement. The sensitivity of the observable to the strong coupling constant [Formula: see text] is studied. A fit to all data points with 3-jet masses larger than 664 GeV gives a value of the strong coupling constant of [Formula: see text].
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Search for decays of stopped long-lived particles produced in proton-proton collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:151. [PMID: 25983648 PMCID: PMC4423862 DOI: 10.1140/epjc/s10052-015-3367-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/19/2015] [Indexed: 06/04/2023]
Abstract
A search has been performed for long-lived particles that could have come to rest within the CMS detector, using the time intervals between LHC beam crossings. The existence of such particles could be deduced from observation of their decays via energy deposits in the CMS calorimeter appearing at times that are well separated from any proton-proton collisions. Using a data set corresponding to an integrated luminosity of 18.6[Formula: see text] of 8[Formula: see text] proton-proton collisions, and a search interval corresponding to 281 h of trigger livetime, 10 events are observed, with a background prediction of [Formula: see text] events. Limits are presented at 95 % confidence level on gluino and top squark production, for over 13 orders of magnitude in the mean proper lifetime of the stopped particle. Assuming a cloud model of R-hadron interactions, a gluino with mass [Formula: see text]1000[Formula: see text] and a top squark with mass [Formula: see text]525[Formula: see text] are excluded, for lifetimes between 1 [Formula: see text]s and 1000[Formula: see text]. These results are the most stringent constraints on stopped particles to date.
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Measurements of differential and double-differential Drell-Yan cross sections in proton-proton collisions at [Formula: see text][Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:147. [PMID: 26041973 PMCID: PMC4446050 DOI: 10.1140/epjc/s10052-015-3364-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/19/2015] [Indexed: 05/22/2023]
Abstract
Measurements of the differential and double-differential Drell-Yan cross sections in the dielectron and dimuon channels are presented. They are based on proton-proton collision data at [Formula: see text] recorded with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7[Formula: see text]. The measured inclusive cross section in the [Formula: see text] peak region (60-120[Formula: see text]), obtained from the combination of the dielectron and dimuon channels, is [Formula: see text], where the statistical uncertainty is negligible. The differential cross section [Formula: see text] in the dilepton mass range 15-2000[Formula: see text] is measured and corrected to the full phase space. The double-differential cross section [Formula: see text] is also measured over the mass range 20 to 1500[Formula: see text] and absolute dilepton rapidity from 0 to 2.4. In addition, the ratios of the normalized differential cross sections measured at [Formula: see text] and 8[Formula: see text] are presented. These measurements are compared to the predictions of perturbative QCD at next-to-leading and next-to-next-to-leading (NNLO) orders using various sets of parton distribution functions (PDFs). The results agree with the NNLO theoretical predictions computed with fewz 3.1 using the CT10 NNLO and NNPDF2.1 NNLO PDFs. The measured double-differential cross section and ratio of normalized differential cross sections are sufficiently precise to constrain the proton PDFs.
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Search for supersymmetry using razor variables in events withb-tagged jets inppcollisions ats=8 TeV. Int J Clin Exp Med 2015. [DOI: 10.1103/physrevd.91.052018] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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