A dynamic imaging method for monitoring self-potential data was proposed.Based on the Darcy’s law and Archie’sformulas,a dynamic model was built as a state model to simulate the transportation of metallic ions in po...A dynamic imaging method for monitoring self-potential data was proposed.Based on the Darcy’s law and Archie’sformulas,a dynamic model was built as a state model to simulate the transportation of metallic ions in porous medium,and theNernst equation was used to calculate the redox potential of metallic ions for observation modeling.Then,the state model andobservation model form an extended Kalman filter cycle to perform dynamic imaging.The noise added synthetic data imaging testshows that the extended Kalman filter can effectively fuse the model evolution and observed self-potential data.The further sandboxmonitoring experiment also demonstrates that the self-potential can be used to monitor the activities of metallic ions and exactlyretrieve the dynamic process of metallic contamination.展开更多
Objective:To compare the clinical value of dynamic contrast-enhanced MRI(DCE-MRI)and single-photon emission computed tomography(SPECT)renal dynamic imaging in the measurement of glomerular filtration rate(GFR)in the e...Objective:To compare the clinical value of dynamic contrast-enhanced MRI(DCE-MRI)and single-photon emission computed tomography(SPECT)renal dynamic imaging in the measurement of glomerular filtration rate(GFR)in the evaluation of renal function in renal transplantation.Methods:A total of 70 recipients who underwent renal transplantation in Baogang Hospital of Inner Mongolia from April of 2015 to April of 2018 were selected as research objects.GFR was measured in renal transplant recipients by use of DCE-MRI and SPECT(GFR-MRI and GFR-SPECT respectively),and was compared with creatinine clearance rate(Ccr).The safety of contrast media was evaluated in DCE-MRI detection.Results:The bias of GFR-MRI against Ccr value was higher than that of GFR-SPECT against Ccr value,with 30%and 50%accuracy of GFR-MRI higher than that of GFR-SPECT,and the difference was statistically significant(p<.05).Pearson correlation analysis showed that GFR-MRI and GFR-SPECT values were positively correlated to Ccr(p<.05),and the correlation coefficient of GFR-MRI and Ccr was higher than that of GFR-SPECT and Ccr,with the difference statistically significant(p<.05).By Bland-Altman analysis,95%confidence interval of GFR-SPECT was 95.49 ml/(min·1.73 m^(2)),and 95%confidence interval of GFR-MRI was 62.35 ml/(min·1.73m^(2)),which was much narrower.Only 2 cases of patients developed mild rash among 70 cases of patients,and recovered spontaneously without any treatment.Conclusions:Compared with SPECT,the bias of GFR measured by DCE-MRI against Ccr is much greater.However,DCE-MRI has a higher accuracy,correlation and consistency in comparison with Ccr,and it has a narrower confidence interval.DCE-MRI can more accurately evaluate renal function in renal transplantation by measuring GFR,and it has a high safety.展开更多
Dynamic imaging modes are increasingly crucial for agile satellites to perform complicated Earth observation tasks.In this study,a direct guidance algorithm is developed to calculate the reference attitude and velocit...Dynamic imaging modes are increasingly crucial for agile satellites to perform complicated Earth observation tasks.In this study,a direct guidance algorithm is developed to calculate the reference attitude and velocity for dynamic imaging mode from target geolocation information while considering the constraints on both the satellite camera boresight axis and the image motion vector.The two slew angles are determined directly,and no rotation around the boresight or reference vector is required.The proposed approach employs a direct solution instead of the iterative process to obtain the reference attitude,which releases the onboard control system from the intensive computational load.To illustrate the performance of the proposed guidance algorithms,numerical simulation results are presented.展开更多
Monitoring the dynamics of cellular pseudopodia at nanoscale has become essential for understanding their diverse and complex functions in living cells.This is made possible by combining single-molecule localization m...Monitoring the dynamics of cellular pseudopodia at nanoscale has become essential for understanding their diverse and complex functions in living cells.This is made possible by combining single-molecule localization microscopy(SMLM)with self-blinking dyes.However,existing self-blinking dyes often face limitations,such as nonspecific blinking and low photostability,which can bring background noise and yield erroneous localization signals,hindering their effectiveness for nanoscale visualization.Here,we present a method for long-term SMLM imaging of cellular pseudopodia dynamics using a blinkogenic probe that exhibits self-blinking activation upon molecular recognition.This approach enabled the precise tracking of various pseudopodia structures,including filopodia,lamellipodia,and(tunneling nanotubes)-nanoscale(TNTs),in living cells.We monitored the growth and fusion of filopodia,as well as the extension and shrinkage of lamellipodia,in real-time.Additionally,we identified two distinct fusion modes between filopodia and lamellipodia and captured the formation of TNTs and their interactions with filopodia,demonstrating the probe's utility in visualizing real-time pseudopodia dynamics at nanoscale.展开更多
Three-dimensional (3D) visualization of dynamic biological processes in deep tissue remains challenging due to the trade-off between temporal resolution and imaging depth. Here, we present a novel near-infrared-II (NI...Three-dimensional (3D) visualization of dynamic biological processes in deep tissue remains challenging due to the trade-off between temporal resolution and imaging depth. Here, we present a novel near-infrared-II (NIR-II, 900–1880nm) fluorescence volumetric microscopic imaging method that combines an electrically tunable lens (ETL) with deep learning approaches for rapid 3D imaging. The technology achieves volumetric imaging at 4.2 frames per second (fps) across a 200 μm depth range in live mouse brain vasculature. Two specialized neural networks are utilized: a scale-recurrent network (SRN) for image enhancement and a cerebral vessel interpolation (CVI) network that enables 16-fold axial upsampling. The SRN, trained on two-photon fluorescence microscopic data, improves both lateral and axial resolution of NIR-II fluorescence wide-field microscopic images. The CVI network, adapted from video interpolation techniques, generates intermediate frames between acquired axial planes, resulting in smooth and continuous 3D vessel reconstructions. Using this integrated system, we visualize and quantify blood flow dynamics in individual vessels and are capable of measuring blood velocity at different depths. This approach maintains high lateral resolution while achieving rapid volumetric imaging, and is particularly suitable for studying dynamic vascular processes in deep tissue. Our method demonstrates the potential of combining optical engineering with artificial intelligence to advance biological imaging capabilities.展开更多
BACKGROUND Colorectal cancer stands among the most prevalent digestive system malignancies.The microsatellite instability(MSI)profile plays a crucial role in determining patient outcomes and therapy responsiveness.Tra...BACKGROUND Colorectal cancer stands among the most prevalent digestive system malignancies.The microsatellite instability(MSI)profile plays a crucial role in determining patient outcomes and therapy responsiveness.Traditional MSI evaluation methods require invasive tissue sampling,are lengthy,and can be compromised by intratumoral heterogeneity.AIM To establish a non-invasive technique utilizing dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)radiomics and machine learning algorithms to determine MSI status in patients with intermediate-stage rectal cancer.METHODS This retrospective analysis examined 120 individuals diagnosed with stage II/III rectal cancer[30 MSI-high(MSI-H)and 90 microsatellite stability(MSS)/MSI-low(MSI-L)cases].We extracted comprehensive radiomics signatures from DCE-MRI scans,encompassing textural parameters that reflect tumor heterogeneity,shapebased metrics,and histogram-derived statistical values.Least absolute shrinkage and selection operator regression facilitated feature selection,while predictive frameworks were developed using various classification algorithms(logistic regression,support vector machine,and random forest).Performance assessment utilized separate training and validation cohorts.RESULTS Our investigation uncovered distinctive imaging characteristics between MSI-H and MSS/MSI-L neoplasms.MSIH tumors exhibited significantly elevated entropy values(7.84±0.92 vs 6.39±0.83,P=0.004),enhanced surface-tovolume proportions(0.72±0.14 vs 0.58±0.11,P=0.008),and heightened signal intensity variation(3642±782 vs 2815±645,P=0.007).The random forest model demonstrated superior classification capability with area under the curves(AUCs)of 0.891 and 0.896 across training and validation datasets,respectively.An integrated approach combining radiomics with clinical parameters further enhanced performance metrics(AUC 0.923 and 0.914),achieving 88.5%sensitivity alongside 87.2%specificity.CONCLUSION DCE-MRI radiomics features interpreted through machine learning frameworks offer an effective strategy for MSI status assessment in intermediate-stage rectal cancer.展开更多
BACKGROUND Rectal cancer requires accurate preoperative assessment of T stage and differentiation grade for treatment planning.Traditional imaging and serum markers have limitations in diagnostic accuracy.AIM To evalu...BACKGROUND Rectal cancer requires accurate preoperative assessment of T stage and differentiation grade for treatment planning.Traditional imaging and serum markers have limitations in diagnostic accuracy.AIM To evaluate the predictive value of dynamic contrast-enhanced-magnetic resonance imaging(DCE-MRI)parameters and serum biomarkers[carbohydrate antigen(CA)19-9,CA125]for determining T stage and differentiation grade in rectal cancer.METHODS We conducted a retrospective review of clinical data from 126 patients who were pathologically diagnosed with rectal cancer between January 2021 to June 2024.Each patient underwent DCE-MRI scans and serum tests for CA19-9 and CA125.Receiver operating characteristic curves were utilized to assess the diagnostic value of DCE-MRI parameters,including volume transfer constant(Ktrans),rate constant(Kep),and volume fraction of extravascular extracellular space(Ve),as well as serum biomarkers for staging and grading rectal cancer.The DeLong test algorithm was employed to evaluate differences in diagnostic performance among the various indicators.RESULTS There were statistically higher levels of Ktrans,Ve,CA19-9,and CA125 serum concentrations of patients with advanced T stages and on poorly differentiated tumors than that in patients with low stages and moderate to high differentiation(P<0.05).Combined use of Ktrans and Ve for T stage diagnosis showed an area under the curve(AUC)of 0.892[95%confidence interval(CI):0.832-0.952],which increased to 0.923(95%CI:0.865-0.981)when combined with serum biomarkers.For grades differentiation,the combined DCE-MRI parameters had an AUC of 0.883(95%CI:0.821-0.945),which rose to 0.912(95%CI:0.855-0.969)when combined with serum markers.According to the Delong test,the combined diagnostic method performed better than a single diagnostic method(P<0.05).CONCLUSION The combined application of DCE-MRI functional parameters and serum tumor markers can significantly improve the diagnostic accuracy of T staging and differentiation degree of rectal cancer,providing a new approach to improve the preoperative assessment system of rectal cancer.This combined diagnostic model has important clinical application value,but further validation is needed through large-scale multicenter studies.展开更多
BACKGROUND The role of cerebral microvascular dysfunction in early cognitive impairment and dementia has become increasingly recognized.Furthermore,pathological changes in both Alzheimer’s disease and vascular dement...BACKGROUND The role of cerebral microvascular dysfunction in early cognitive impairment and dementia has become increasingly recognized.Furthermore,pathological changes in both Alzheimer’s disease and vascular dementia are almost always associated with cerebral hemodynamic deficits.AIM To investigate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)assessment of the blood-brain barrier(BBB)in combination with relevant plasma biomarkers for mild cognitive impairment(MCI).METHODS This study selected 50 patients with non-amnestic MCI(na-MCI group),52 patients with amnestic MCI(a-MCI group),and 55 healthy elderly controls(control group).The Chinese version of the Montreal cognitive assessment(MoCA),auditory verbal learning test(AVLT),Hamilton anxiety/depression scale(HAMA/HAMD),and activity of daily living(ADL)scales were used to analyze the characteristics of mental and behavioral symptoms of patients with MCI.The DCE-MRI technique was used to assess the contrast enhancement kinetics.The Patlak model was utilized to analyze the BBB permeability(volume transfer constants).Further,fasting blood was was used to quantify plasma homocysteine(Hcy),β-amyloid protein(Aβ)40,Aβ42,human phosphorylated tau-181 protein(p-tau181),intercellular adhesion molecule-1(ICAM-1),vascular cell adhesion molecule-1(VCAM-1),and plasminogen activator inhibitor-1(PAI-1)levels,as well as serum neurofilament light chain(NFL)and glial fibrillary acidic protein(GFAP)concentrations.RESULTS The na-MCI and a-MCI groups demonstrated significantly lower MoCA and AVLT-Huashan version scores,and statistically higher HAMA,HAMD,and ADL scores compared to the control group.Moreover,the a-MCI group showed notably higher HAMA,HAMD,and ADL scores compared to the na-MCI group.Cranial MRI results revealed significant disparities in cerebral blood flow in the left and right frontal lobes,temporal lobes,hippocampi,cuneus,precuneus,parietal lobes,basal ganglia,and occipital lobes between the a-MCI and na-MCI groups.Compared to healthy controls,patients with MCI demonstrated a smaller amplitude of hippocampal contrast enhancement kinetics and a slower decay rate,indicating smaller vascular volume and increased BBB permeability.Further,Hcy,p-tau181,ICAM-1,VCAM-1,PAI-1,and NFL levels were substantially higher in the a-MCI group than in the na-MCI group,whereas the Aβ42 level was significantly lower.We did not observe any significant differences in Aβ40 and GFAP levels.CONCLUSION Patients with MCI may have experienced cerebrovascular system changes in the hippocampal region.Disorders associated with changes in cerebral blood supply may begin before pathophysiological changes are visible by imaging,which provides references for the assessment and treatment of patients with cognitive disorders.Further,DCE-MRI provides a noninvasive approach to diagnose subtle BBB leakage associated with cerebrovascular pathology.展开更多
In order to solve the problem that the star point positioning accuracy of the star sensor in near space is decreased due to atmospheric background stray light and rapid maneuvering of platform, this paper proposes a s...In order to solve the problem that the star point positioning accuracy of the star sensor in near space is decreased due to atmospheric background stray light and rapid maneuvering of platform, this paper proposes a star point positioning algorithm based on the capsule network whose input and output are both vectors. First, a PCTL (Probability-Coordinate Transformation Layer) is designed to represent the mapping relationship between the probability output of the capsule network and the star point sub-pixel coordinates. Then, Coordconv Layer is introduced to implement explicit encoding of space information and the probability is used as the centroid weight to achieve the conversion between probability and star point sub-pixel coordinates, which improves the network’s ability to perceive star point positions. Finally, based on the dynamic imaging principle of star sensors and the characteristics of near-space environment, a star map dataset for algorithm training and testing is constructed. The simulation results show that the proposed algorithm reduces the MAE (Mean Absolute Error) and RMSE (Root Mean Square Error) of the star point positioning by 36.1% and 41.7% respectively compared with the traditional algorithm. The research results can provide important theory and technical support for the scheme design, index demonstration, test and evaluation of large dynamic star sensors in near space.展开更多
AIM: To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially...AIM: To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially pancreatic carcinoma coexisting with chronic pancreatitis and tumor-forming pancreatitis. METHODS: Forty-eight consecutive patients who underwent surgery for a focal pancreatic mass, including pancreatic ductal carcinoma (n = 33), tumor-forming pancreatitis (n = 8), and islet cell tumor (n = 7), were reviewed. Five pancreatic carcinomas coexisted with longstanding chronic pancreatitis. The pancreatic TICs were obtained from the pancreatic mass and the pancreatic parenchyma both proximal and distal to the mass lesion in each patient, prior to surgery, and were classified into 4 types according to the time to a peak: 25 s and 1, 2, and 3 min after the bolus injection of contrast material, namely, type-Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively, and were then compared to the corresponding histological pancreatic conditions. RESULTS: Pancreatic carcinomas demonstrated type-Ⅲ (n = 13) or Ⅳ (n = 20) TIC. Tumor-forming pancreatitis showed type-Ⅱ (n = 5) or Ⅲ (n = 3) TIC. All islet cell tumors revealed type-Ⅰ. The type-Ⅳ TIC was only recognized in pancreatic carcinoma, and the TIC of carcinoma always depicted the slowest rise to a peak among the 3 pancreatic TICs measured in each patient, even in patients with chronic pancreatitis.CONCLUSION: Pancreatic TIC from dynamic MRI provides reliable information for distinguishing pancreatic carcinoma from other pancreatic masses, and may enable us to avoid unnecessary pancreatic surgery and delays in making a correct diagnosis of pancreatic carcinoma, especially, in patients with longstanding chronic pancreatitis.展开更多
Preoperative detection of lymph nodes（LNs） metastasis is always highly challenging for radiologists nowadays. The utility of quantitative dynamic contrast-enhanced magnetic resonance imaging（QDCE-MRI） in identifyi...Preoperative detection of lymph nodes（LNs） metastasis is always highly challenging for radiologists nowadays. The utility of quantitative dynamic contrast-enhanced magnetic resonance imaging（QDCE-MRI） in identifying LNs metastasis is not well understood. In the present study, 59 patients with histologically proven rectal carcinoma underwent preoperative QDCE-MRI. The short axis diameter ratio, long axis diameter ratio, short-to-long axis diameter ratio and QDEC-MRI parameters（Ktrans, Kep, fPV and Ve） values were compared between the non-metastatic（n=44） and metastatic（n=35） LNs groups based on pathological examination. Compared with the non-metastatic group, the metastatic group exhibited significantly higher short axis diameter（7.558±0.668 mm vs. 5.427±0.285 mm）, Ktrans（0.483±0.198 min-1 vs. 0.218±0.116 min^-1） and Ve（0.399±0.118 vs. 0.203±0.096） values（all P〈0.05）. The short-to-long axis diameter ratio, long axis diameter ratio, Kep and fPV values did not show significant differences between the two groups. In conclusion, our results showed that for LNs larger than 5 mm in rectal cancer, there are distinctive differences in the Ktrans and Ve values between the metastatic and non-metastatic LNs, suggesting that QDCE-MRI may be potentially helpful in identifying LNs status.展开更多
Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） ...Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） germ cell tumors（GCTs）.Methods： DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic（ROC） curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results： A significant elevation in transfer constant（K^trans） and extravascular extracellular space（Ve）（P=0.000）, as well as a significant reduction in rate constant（Kep）（P=0.000） was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value（PPV） of 95.8%, and negative predictive value（NPV） of 100%.Conclusions： Relative K^trans appeared promising in predicting tumor response to radiation therapy（RT）. It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.展开更多
In many areas of oncology, dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) has proven to be a clinically useful, non-invasive functional imaging technique to quantify tumor vasculature and tumor perfusio...In many areas of oncology, dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) has proven to be a clinically useful, non-invasive functional imaging technique to quantify tumor vasculature and tumor perfusion characteristics. Tumor angiogenesis is an essential process for tumor growth, proliferation, and metastasis. Malignant lesions demonstrate rapid extravasation of contrast from the intravascular space to the capillary bed due to leaky capillaries associated with tumor neovascularity. DCE-MRI has the potential to provide information regarding blood flow, areas of hypoperfusion, and variations in endothelial permeability and microvessel density to aid treatment selection, enable frequent monitoring during treatment and assess response to targeted therapy following treatment. This review will discuss the current status of DCE-MRI in cancer imaging, with a focus on its use in imaging prostate malignancies as well as weaknesses that limit its widespread clinical use. The latest techniques for quantification of DCE-MRI parameters will be reviewed and compared.展开更多
BACKGROUND: AND PURPOSE: The measurement of relative cerebral blood volume (rCBV) and the volume transfer constant (K(trans)) by means of dynamic contrast-enhanced (DCE) perfusion MR imaging (pMRI) can be useful in ch...BACKGROUND: AND PURPOSE: The measurement of relative cerebral blood volume (rCBV) and the volume transfer constant (K(trans)) by means of dynamic contrast-enhanced (DCE) perfusion MR imaging (pMRI) can be useful in characterizing brain tumors. The purpose of our study was to evaluate the utility of these measurements in differentiating typical meningiomas and atypical meningiomas. METHODS: Fifteen patients with pathologically confirmed typical meningiomas and seven with atypical meningiomas underwent conventional imaging and DCE pMRI before resection.rCBV measurements were calculated by using standard intravascular展开更多
The fast X-ray imaging beamline(BL16U2)at Shanghai Synchrotron Radiation Facility(SSRF)is a new beamline that provides X-ray micro-imaging capabilities across a wide range of time scales,spanning from 100 ps toμs and...The fast X-ray imaging beamline(BL16U2)at Shanghai Synchrotron Radiation Facility(SSRF)is a new beamline that provides X-ray micro-imaging capabilities across a wide range of time scales,spanning from 100 ps toμs and ms.This beamline has been specifically designed to facilitate the investigation of a wide range of rapid phenomena,such as the deformation and failure of materials subjected to intense dynamic loads.In addition,it enables the study of high-pressure and high-speed fuel spray processes in automotive engines.The light source of this beamline is a cryogenic permanent magnet undulator(CPMU)that is cooled by liquid nitrogen.This CPMU can generate X-ray photons within an energy range of 8.7-30 keV.The beamline offers two modes of operation:monochromatic beam mode with a liquid nitrogen-cooled double-crystal monochromator(DCM)and pink beam mode with the first crystal of the DCM out of the beam path.Four X-ray imaging methods were implemented in BL16U2:single-pulse ultrafast X-ray imaging,microsecond-resolved X-ray dynamic imaging,millisecond-resolved X-ray dynamic micro-CT,and high-resolution quantitative micro-CT.Furthermore,BL16U2 is equipped with various in situ impact loading systems,such as a split Hopkinson bar system,light gas gun,and fuel spray chamber.Following the completion of the final commissioning in 2021 and subsequent trial operations in 2022,the beamline has been officially available to users from 2023.展开更多
We report direct nanoscale imaging of ultrafast plasmon in a gold dolmen nanostructure excited with the 7is laser pulses by combining the interferometric time-resolved technology with the three-photon photoemission el...We report direct nanoscale imaging of ultrafast plasmon in a gold dolmen nanostructure excited with the 7is laser pulses by combining the interferometric time-resolved technology with the three-photon photoemission electron microscopy （PEEM）. The interferometric time-resolved traces show that the plasmon mode beating pattern appears at the ends of the dimer slabs in the dolmen nanostructure as a result of coherent superposition of multiple localized surface plasmon modes induced by broad bandwidth of the ultrafast laser pulses. The PEEM measurement further discloses that in-phase of the oscillation field of two neighbor defects are surprisingly observed, which is attributed to the plasmon coupling between them. Furthermore, the control of the temporal delay between the pump and probe laser pluses could be utilized for manipulation of the near-field distribution. These findings deepen our understanding of ultrafast plasmon dynamics in a complex nanosystem.展开更多
Breast cancer represents the most common malignancy in women,being one of the most frequent cause of cancer-related mortality.Ultrasound,mammography,and magnetic resonance imaging(MRI)play a pivotal role in the diagno...Breast cancer represents the most common malignancy in women,being one of the most frequent cause of cancer-related mortality.Ultrasound,mammography,and magnetic resonance imaging(MRI)play a pivotal role in the diagnosis of breast lesions,with different levels of accuracy.Particularly,dynamic contrastenhanced MRI has shown high diagnostic value in detecting multifocal,multicentric,or contralateral breast cancers.Radiomics is emerging as a promising tool for quantitative tumor evaluation,allowing the extraction of additional quantitative data from radiological imaging acquired with different modalities.Radiomics analysis may provide novel information through the quantification of lesions heterogeneity,that may be relevant in clinical practice for the characterization of breast lesions,prediction of tumor response to systemic therapies and evaluation of prognosis in patients with breast cancers.Several published studies have explored the value of radiomics with good-to-excellent diagnostic and prognostic performances for the evaluation of breast lesions.Particularly,the integrations of radiomics data with other clinical and histopathological parameters have demonstrated to improve the prediction of tumor aggressiveness with high accuracy and provided precise models that will help to guide clinical decisions and patients management.The purpose of this article in to describe the current application of radiomics in breast dynamic contrast-enhanced MRI.展开更多
We experimentally observe the dynamic evolution of atoms in the evaporative cooling, by in-situ imaging the plugged hole of ultracold atoms. Ultracold rubidium atoms confined in a magnetic trap are plugged using a blu...We experimentally observe the dynamic evolution of atoms in the evaporative cooling, by in-situ imaging the plugged hole of ultracold atoms. Ultracold rubidium atoms confined in a magnetic trap are plugged using a blue-detuned laser beam with a waist of 20 m at a wavelength of 767 nm. We probe the variation of the atomic temperature and width versus the radio frequency in the evaporative cooling. Both the behaviors are in good agreement with the calculation of the trapping potential dressed by the rf signal above the threshold temperature,while deviating from the calculation near the phase transition. To accurately obtain the atomic width, we use the plugged hole as the reference to optimize the optical imaging system by precisely minimizing the artificial structures due to the defocus effect.展开更多
Artificial Intelligence (AI) expands its recognition rapidly through the past few years in the context of generating content dynamically, remarkably challenging the human creativity. This study aims to evaluate the ef...Artificial Intelligence (AI) expands its recognition rapidly through the past few years in the context of generating content dynamically, remarkably challenging the human creativity. This study aims to evaluate the efficacy of AI in enhancing personal branding for musicians, particularly in crafting brand images based on emotions received from the artist’s music will improve the audience perceptions regarding the artist’s brand. Study used a quantitative approach for the research, gathering primary data from the survey of 191 people—music lovers, musicians and music producers. The survey focuses on preferences, perceptions, and behaviours related to music consumption and artist branding. The study results demonstrate the awareness and understanding of AI’s role in personal branding within the music industry. Also, results indicate that such an adaptive approach enhances audience perceptions of the artist and strengthens emotional connections. Furthermore, over 50% of the participants indicated a desire to attend live events where an artist’s brand image adapts dynamically to their emotions. The study focuses on novel approaches in personal branding based on the interaction of AI-driven emotional data. In contrast to traditional branding concepts, this study indicates that AI can suggest dynamic and emotionally resonant brand identities for artists. The real time audience response gives proper guidance for the decision-making. This study enriches the knowledge of AI’s applicability to branding processes in the context of the music industry and opens the possibilities for additional advancements in building emotionally appealing brand identities.展开更多
An improved estimation of motion vectors of feature points is proposed for tracking moving objects of dynamic image sequence. Feature points are firstly extracted by the improved minimum intensity change （MIC） algor...An improved estimation of motion vectors of feature points is proposed for tracking moving objects of dynamic image sequence. Feature points are firstly extracted by the improved minimum intensity change （MIC） algorithm. The matching points of these feature points are then determined by adaptive rood pattern searching. Based on the random sample consensus （RANSAC） method, the background motion is finally compensated by the parameters of an affine transform of the background motion. With reasonable morphological filtering, the moving objects are completely extracted from the background, and then tracked accurately. Experimental results show that the improved method is successful on the motion background compensation and offers great promise in tracking moving objects of the dynamic image sequence.展开更多
基金Project(41574123)supported by the National Natural Science Foundation of ChinaProject(2013FY110800)supported by the National Basic Research Scientific Program of China
文摘A dynamic imaging method for monitoring self-potential data was proposed.Based on the Darcy’s law and Archie’sformulas,a dynamic model was built as a state model to simulate the transportation of metallic ions in porous medium,and theNernst equation was used to calculate the redox potential of metallic ions for observation modeling.Then,the state model andobservation model form an extended Kalman filter cycle to perform dynamic imaging.The noise added synthetic data imaging testshows that the extended Kalman filter can effectively fuse the model evolution and observed self-potential data.The further sandboxmonitoring experiment also demonstrates that the self-potential can be used to monitor the activities of metallic ions and exactlyretrieve the dynamic process of metallic contamination.
文摘Objective:To compare the clinical value of dynamic contrast-enhanced MRI(DCE-MRI)and single-photon emission computed tomography(SPECT)renal dynamic imaging in the measurement of glomerular filtration rate(GFR)in the evaluation of renal function in renal transplantation.Methods:A total of 70 recipients who underwent renal transplantation in Baogang Hospital of Inner Mongolia from April of 2015 to April of 2018 were selected as research objects.GFR was measured in renal transplant recipients by use of DCE-MRI and SPECT(GFR-MRI and GFR-SPECT respectively),and was compared with creatinine clearance rate(Ccr).The safety of contrast media was evaluated in DCE-MRI detection.Results:The bias of GFR-MRI against Ccr value was higher than that of GFR-SPECT against Ccr value,with 30%and 50%accuracy of GFR-MRI higher than that of GFR-SPECT,and the difference was statistically significant(p<.05).Pearson correlation analysis showed that GFR-MRI and GFR-SPECT values were positively correlated to Ccr(p<.05),and the correlation coefficient of GFR-MRI and Ccr was higher than that of GFR-SPECT and Ccr,with the difference statistically significant(p<.05).By Bland-Altman analysis,95%confidence interval of GFR-SPECT was 95.49 ml/(min·1.73 m^(2)),and 95%confidence interval of GFR-MRI was 62.35 ml/(min·1.73m^(2)),which was much narrower.Only 2 cases of patients developed mild rash among 70 cases of patients,and recovered spontaneously without any treatment.Conclusions:Compared with SPECT,the bias of GFR measured by DCE-MRI against Ccr is much greater.However,DCE-MRI has a higher accuracy,correlation and consistency in comparison with Ccr,and it has a narrower confidence interval.DCE-MRI can more accurately evaluate renal function in renal transplantation by measuring GFR,and it has a high safety.
基金sponsored by the Shanghai Sailing Program 17YF1408300 and 17YF1408400the National Natural Science Foundation of China under Grant Nos.U20B2054 and U20B2056.
文摘Dynamic imaging modes are increasingly crucial for agile satellites to perform complicated Earth observation tasks.In this study,a direct guidance algorithm is developed to calculate the reference attitude and velocity for dynamic imaging mode from target geolocation information while considering the constraints on both the satellite camera boresight axis and the image motion vector.The two slew angles are determined directly,and no rotation around the boresight or reference vector is required.The proposed approach employs a direct solution instead of the iterative process to obtain the reference attitude,which releases the onboard control system from the intensive computational load.To illustrate the performance of the proposed guidance algorithms,numerical simulation results are presented.
基金supported by the National Natural Science Foundation of China(Nos.22225806,22078314,22278394,22378385)Dalian Institute of Chemical Physics(Nos.DICPI202227,DICPI202436)。
文摘Monitoring the dynamics of cellular pseudopodia at nanoscale has become essential for understanding their diverse and complex functions in living cells.This is made possible by combining single-molecule localization microscopy(SMLM)with self-blinking dyes.However,existing self-blinking dyes often face limitations,such as nonspecific blinking and low photostability,which can bring background noise and yield erroneous localization signals,hindering their effectiveness for nanoscale visualization.Here,we present a method for long-term SMLM imaging of cellular pseudopodia dynamics using a blinkogenic probe that exhibits self-blinking activation upon molecular recognition.This approach enabled the precise tracking of various pseudopodia structures,including filopodia,lamellipodia,and(tunneling nanotubes)-nanoscale(TNTs),in living cells.We monitored the growth and fusion of filopodia,as well as the extension and shrinkage of lamellipodia,in real-time.Additionally,we identified two distinct fusion modes between filopodia and lamellipodia and captured the formation of TNTs and their interactions with filopodia,demonstrating the probe's utility in visualizing real-time pseudopodia dynamics at nanoscale.
基金supported by the National Key R&D Program of China (No. 2024YFF1206700)the National Natural Science Foundation of China (No. U23A20487)the Hangzhou Chengxi Sci-tech Innovation Corridor Management Committee.
文摘Three-dimensional (3D) visualization of dynamic biological processes in deep tissue remains challenging due to the trade-off between temporal resolution and imaging depth. Here, we present a novel near-infrared-II (NIR-II, 900–1880nm) fluorescence volumetric microscopic imaging method that combines an electrically tunable lens (ETL) with deep learning approaches for rapid 3D imaging. The technology achieves volumetric imaging at 4.2 frames per second (fps) across a 200 μm depth range in live mouse brain vasculature. Two specialized neural networks are utilized: a scale-recurrent network (SRN) for image enhancement and a cerebral vessel interpolation (CVI) network that enables 16-fold axial upsampling. The SRN, trained on two-photon fluorescence microscopic data, improves both lateral and axial resolution of NIR-II fluorescence wide-field microscopic images. The CVI network, adapted from video interpolation techniques, generates intermediate frames between acquired axial planes, resulting in smooth and continuous 3D vessel reconstructions. Using this integrated system, we visualize and quantify blood flow dynamics in individual vessels and are capable of measuring blood velocity at different depths. This approach maintains high lateral resolution while achieving rapid volumetric imaging, and is particularly suitable for studying dynamic vascular processes in deep tissue. Our method demonstrates the potential of combining optical engineering with artificial intelligence to advance biological imaging capabilities.
基金Supported by the Natural Science Foundation of Fujian Province,China,No.2022J011460。
文摘BACKGROUND Colorectal cancer stands among the most prevalent digestive system malignancies.The microsatellite instability(MSI)profile plays a crucial role in determining patient outcomes and therapy responsiveness.Traditional MSI evaluation methods require invasive tissue sampling,are lengthy,and can be compromised by intratumoral heterogeneity.AIM To establish a non-invasive technique utilizing dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)radiomics and machine learning algorithms to determine MSI status in patients with intermediate-stage rectal cancer.METHODS This retrospective analysis examined 120 individuals diagnosed with stage II/III rectal cancer[30 MSI-high(MSI-H)and 90 microsatellite stability(MSS)/MSI-low(MSI-L)cases].We extracted comprehensive radiomics signatures from DCE-MRI scans,encompassing textural parameters that reflect tumor heterogeneity,shapebased metrics,and histogram-derived statistical values.Least absolute shrinkage and selection operator regression facilitated feature selection,while predictive frameworks were developed using various classification algorithms(logistic regression,support vector machine,and random forest).Performance assessment utilized separate training and validation cohorts.RESULTS Our investigation uncovered distinctive imaging characteristics between MSI-H and MSS/MSI-L neoplasms.MSIH tumors exhibited significantly elevated entropy values(7.84±0.92 vs 6.39±0.83,P=0.004),enhanced surface-tovolume proportions(0.72±0.14 vs 0.58±0.11,P=0.008),and heightened signal intensity variation(3642±782 vs 2815±645,P=0.007).The random forest model demonstrated superior classification capability with area under the curves(AUCs)of 0.891 and 0.896 across training and validation datasets,respectively.An integrated approach combining radiomics with clinical parameters further enhanced performance metrics(AUC 0.923 and 0.914),achieving 88.5%sensitivity alongside 87.2%specificity.CONCLUSION DCE-MRI radiomics features interpreted through machine learning frameworks offer an effective strategy for MSI status assessment in intermediate-stage rectal cancer.
文摘BACKGROUND Rectal cancer requires accurate preoperative assessment of T stage and differentiation grade for treatment planning.Traditional imaging and serum markers have limitations in diagnostic accuracy.AIM To evaluate the predictive value of dynamic contrast-enhanced-magnetic resonance imaging(DCE-MRI)parameters and serum biomarkers[carbohydrate antigen(CA)19-9,CA125]for determining T stage and differentiation grade in rectal cancer.METHODS We conducted a retrospective review of clinical data from 126 patients who were pathologically diagnosed with rectal cancer between January 2021 to June 2024.Each patient underwent DCE-MRI scans and serum tests for CA19-9 and CA125.Receiver operating characteristic curves were utilized to assess the diagnostic value of DCE-MRI parameters,including volume transfer constant(Ktrans),rate constant(Kep),and volume fraction of extravascular extracellular space(Ve),as well as serum biomarkers for staging and grading rectal cancer.The DeLong test algorithm was employed to evaluate differences in diagnostic performance among the various indicators.RESULTS There were statistically higher levels of Ktrans,Ve,CA19-9,and CA125 serum concentrations of patients with advanced T stages and on poorly differentiated tumors than that in patients with low stages and moderate to high differentiation(P<0.05).Combined use of Ktrans and Ve for T stage diagnosis showed an area under the curve(AUC)of 0.892[95%confidence interval(CI):0.832-0.952],which increased to 0.923(95%CI:0.865-0.981)when combined with serum biomarkers.For grades differentiation,the combined DCE-MRI parameters had an AUC of 0.883(95%CI:0.821-0.945),which rose to 0.912(95%CI:0.855-0.969)when combined with serum markers.According to the Delong test,the combined diagnostic method performed better than a single diagnostic method(P<0.05).CONCLUSION The combined application of DCE-MRI functional parameters and serum tumor markers can significantly improve the diagnostic accuracy of T staging and differentiation degree of rectal cancer,providing a new approach to improve the preoperative assessment system of rectal cancer.This combined diagnostic model has important clinical application value,but further validation is needed through large-scale multicenter studies.
文摘BACKGROUND The role of cerebral microvascular dysfunction in early cognitive impairment and dementia has become increasingly recognized.Furthermore,pathological changes in both Alzheimer’s disease and vascular dementia are almost always associated with cerebral hemodynamic deficits.AIM To investigate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)assessment of the blood-brain barrier(BBB)in combination with relevant plasma biomarkers for mild cognitive impairment(MCI).METHODS This study selected 50 patients with non-amnestic MCI(na-MCI group),52 patients with amnestic MCI(a-MCI group),and 55 healthy elderly controls(control group).The Chinese version of the Montreal cognitive assessment(MoCA),auditory verbal learning test(AVLT),Hamilton anxiety/depression scale(HAMA/HAMD),and activity of daily living(ADL)scales were used to analyze the characteristics of mental and behavioral symptoms of patients with MCI.The DCE-MRI technique was used to assess the contrast enhancement kinetics.The Patlak model was utilized to analyze the BBB permeability(volume transfer constants).Further,fasting blood was was used to quantify plasma homocysteine(Hcy),β-amyloid protein(Aβ)40,Aβ42,human phosphorylated tau-181 protein(p-tau181),intercellular adhesion molecule-1(ICAM-1),vascular cell adhesion molecule-1(VCAM-1),and plasminogen activator inhibitor-1(PAI-1)levels,as well as serum neurofilament light chain(NFL)and glial fibrillary acidic protein(GFAP)concentrations.RESULTS The na-MCI and a-MCI groups demonstrated significantly lower MoCA and AVLT-Huashan version scores,and statistically higher HAMA,HAMD,and ADL scores compared to the control group.Moreover,the a-MCI group showed notably higher HAMA,HAMD,and ADL scores compared to the na-MCI group.Cranial MRI results revealed significant disparities in cerebral blood flow in the left and right frontal lobes,temporal lobes,hippocampi,cuneus,precuneus,parietal lobes,basal ganglia,and occipital lobes between the a-MCI and na-MCI groups.Compared to healthy controls,patients with MCI demonstrated a smaller amplitude of hippocampal contrast enhancement kinetics and a slower decay rate,indicating smaller vascular volume and increased BBB permeability.Further,Hcy,p-tau181,ICAM-1,VCAM-1,PAI-1,and NFL levels were substantially higher in the a-MCI group than in the na-MCI group,whereas the Aβ42 level was significantly lower.We did not observe any significant differences in Aβ40 and GFAP levels.CONCLUSION Patients with MCI may have experienced cerebrovascular system changes in the hippocampal region.Disorders associated with changes in cerebral blood supply may begin before pathophysiological changes are visible by imaging,which provides references for the assessment and treatment of patients with cognitive disorders.Further,DCE-MRI provides a noninvasive approach to diagnose subtle BBB leakage associated with cerebrovascular pathology.
文摘In order to solve the problem that the star point positioning accuracy of the star sensor in near space is decreased due to atmospheric background stray light and rapid maneuvering of platform, this paper proposes a star point positioning algorithm based on the capsule network whose input and output are both vectors. First, a PCTL (Probability-Coordinate Transformation Layer) is designed to represent the mapping relationship between the probability output of the capsule network and the star point sub-pixel coordinates. Then, Coordconv Layer is introduced to implement explicit encoding of space information and the probability is used as the centroid weight to achieve the conversion between probability and star point sub-pixel coordinates, which improves the network’s ability to perceive star point positions. Finally, based on the dynamic imaging principle of star sensors and the characteristics of near-space environment, a star map dataset for algorithm training and testing is constructed. The simulation results show that the proposed algorithm reduces the MAE (Mean Absolute Error) and RMSE (Root Mean Square Error) of the star point positioning by 36.1% and 41.7% respectively compared with the traditional algorithm. The research results can provide important theory and technical support for the scheme design, index demonstration, test and evaluation of large dynamic star sensors in near space.
文摘AIM: To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially pancreatic carcinoma coexisting with chronic pancreatitis and tumor-forming pancreatitis. METHODS: Forty-eight consecutive patients who underwent surgery for a focal pancreatic mass, including pancreatic ductal carcinoma (n = 33), tumor-forming pancreatitis (n = 8), and islet cell tumor (n = 7), were reviewed. Five pancreatic carcinomas coexisted with longstanding chronic pancreatitis. The pancreatic TICs were obtained from the pancreatic mass and the pancreatic parenchyma both proximal and distal to the mass lesion in each patient, prior to surgery, and were classified into 4 types according to the time to a peak: 25 s and 1, 2, and 3 min after the bolus injection of contrast material, namely, type-Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively, and were then compared to the corresponding histological pancreatic conditions. RESULTS: Pancreatic carcinomas demonstrated type-Ⅲ (n = 13) or Ⅳ (n = 20) TIC. Tumor-forming pancreatitis showed type-Ⅱ (n = 5) or Ⅲ (n = 3) TIC. All islet cell tumors revealed type-Ⅰ. The type-Ⅳ TIC was only recognized in pancreatic carcinoma, and the TIC of carcinoma always depicted the slowest rise to a peak among the 3 pancreatic TICs measured in each patient, even in patients with chronic pancreatitis.CONCLUSION: Pancreatic TIC from dynamic MRI provides reliable information for distinguishing pancreatic carcinoma from other pancreatic masses, and may enable us to avoid unnecessary pancreatic surgery and delays in making a correct diagnosis of pancreatic carcinoma, especially, in patients with longstanding chronic pancreatitis.
基金supported by the Provincial Key Clinical Specialty(Medical Imaging)Development Program from Health and Family Planning Commission of Hunan Province,China(No.2015/43)the Health and Family Planning Commission of Hunan Province,China(No.B2016060)the National Key Clinical Specialty(Oncology Department)Development Program from National Health and Family Planning Commission of China(No.2013/544)
文摘Preoperative detection of lymph nodes（LNs） metastasis is always highly challenging for radiologists nowadays. The utility of quantitative dynamic contrast-enhanced magnetic resonance imaging（QDCE-MRI） in identifying LNs metastasis is not well understood. In the present study, 59 patients with histologically proven rectal carcinoma underwent preoperative QDCE-MRI. The short axis diameter ratio, long axis diameter ratio, short-to-long axis diameter ratio and QDEC-MRI parameters（Ktrans, Kep, fPV and Ve） values were compared between the non-metastatic（n=44） and metastatic（n=35） LNs groups based on pathological examination. Compared with the non-metastatic group, the metastatic group exhibited significantly higher short axis diameter（7.558±0.668 mm vs. 5.427±0.285 mm）, Ktrans（0.483±0.198 min-1 vs. 0.218±0.116 min^-1） and Ve（0.399±0.118 vs. 0.203±0.096） values（all P〈0.05）. The short-to-long axis diameter ratio, long axis diameter ratio, Kep and fPV values did not show significant differences between the two groups. In conclusion, our results showed that for LNs larger than 5 mm in rectal cancer, there are distinctive differences in the Ktrans and Ve values between the metastatic and non-metastatic LNs, suggesting that QDCE-MRI may be potentially helpful in identifying LNs status.
基金supported by Beijing Natural Science Foundation(No.7122029)
文摘Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） germ cell tumors（GCTs）.Methods： DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic（ROC） curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results： A significant elevation in transfer constant（K^trans） and extravascular extracellular space（Ve）（P=0.000）, as well as a significant reduction in rate constant（Kep）（P=0.000） was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value（PPV） of 95.8%, and negative predictive value（NPV） of 100%.Conclusions： Relative K^trans appeared promising in predicting tumor response to radiation therapy（RT）. It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.
文摘In many areas of oncology, dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) has proven to be a clinically useful, non-invasive functional imaging technique to quantify tumor vasculature and tumor perfusion characteristics. Tumor angiogenesis is an essential process for tumor growth, proliferation, and metastasis. Malignant lesions demonstrate rapid extravasation of contrast from the intravascular space to the capillary bed due to leaky capillaries associated with tumor neovascularity. DCE-MRI has the potential to provide information regarding blood flow, areas of hypoperfusion, and variations in endothelial permeability and microvessel density to aid treatment selection, enable frequent monitoring during treatment and assess response to targeted therapy following treatment. This review will discuss the current status of DCE-MRI in cancer imaging, with a focus on its use in imaging prostate malignancies as well as weaknesses that limit its widespread clinical use. The latest techniques for quantification of DCE-MRI parameters will be reviewed and compared.
文摘BACKGROUND: AND PURPOSE: The measurement of relative cerebral blood volume (rCBV) and the volume transfer constant (K(trans)) by means of dynamic contrast-enhanced (DCE) perfusion MR imaging (pMRI) can be useful in characterizing brain tumors. The purpose of our study was to evaluate the utility of these measurements in differentiating typical meningiomas and atypical meningiomas. METHODS: Fifteen patients with pathologically confirmed typical meningiomas and seven with atypical meningiomas underwent conventional imaging and DCE pMRI before resection.rCBV measurements were calculated by using standard intravascular
基金supported by the CAS Project for Young Scientists in Basic Research(YSBR-096)the National Major Scientific Instruments and Equipment Development Project of China(No.11627901)+1 种基金the National Key Research and Development Program of China(Nos.2021YFF0701202,2021YFA1600703)the National Natural Science Foundation of China(Nos.U1932205,12275343).
文摘The fast X-ray imaging beamline(BL16U2)at Shanghai Synchrotron Radiation Facility(SSRF)is a new beamline that provides X-ray micro-imaging capabilities across a wide range of time scales,spanning from 100 ps toμs and ms.This beamline has been specifically designed to facilitate the investigation of a wide range of rapid phenomena,such as the deformation and failure of materials subjected to intense dynamic loads.In addition,it enables the study of high-pressure and high-speed fuel spray processes in automotive engines.The light source of this beamline is a cryogenic permanent magnet undulator(CPMU)that is cooled by liquid nitrogen.This CPMU can generate X-ray photons within an energy range of 8.7-30 keV.The beamline offers two modes of operation:monochromatic beam mode with a liquid nitrogen-cooled double-crystal monochromator(DCM)and pink beam mode with the first crystal of the DCM out of the beam path.Four X-ray imaging methods were implemented in BL16U2:single-pulse ultrafast X-ray imaging,microsecond-resolved X-ray dynamic imaging,millisecond-resolved X-ray dynamic micro-CT,and high-resolution quantitative micro-CT.Furthermore,BL16U2 is equipped with various in situ impact loading systems,such as a split Hopkinson bar system,light gas gun,and fuel spray chamber.Following the completion of the final commissioning in 2021 and subsequent trial operations in 2022,the beamline has been officially available to users from 2023.
基金Supported by the National Basic Research Program of China under Grant No 2013CB922404the National Natural Science Foundation of China under Grant Nos 11474040,11474039,61605017 and 61575030the Project of Changchun Science and Technology Bureau under Grant No 14KP007
文摘We report direct nanoscale imaging of ultrafast plasmon in a gold dolmen nanostructure excited with the 7is laser pulses by combining the interferometric time-resolved technology with the three-photon photoemission electron microscopy （PEEM）. The interferometric time-resolved traces show that the plasmon mode beating pattern appears at the ends of the dimer slabs in the dolmen nanostructure as a result of coherent superposition of multiple localized surface plasmon modes induced by broad bandwidth of the ultrafast laser pulses. The PEEM measurement further discloses that in-phase of the oscillation field of two neighbor defects are surprisingly observed, which is attributed to the plasmon coupling between them. Furthermore, the control of the temporal delay between the pump and probe laser pluses could be utilized for manipulation of the near-field distribution. These findings deepen our understanding of ultrafast plasmon dynamics in a complex nanosystem.
文摘Breast cancer represents the most common malignancy in women,being one of the most frequent cause of cancer-related mortality.Ultrasound,mammography,and magnetic resonance imaging(MRI)play a pivotal role in the diagnosis of breast lesions,with different levels of accuracy.Particularly,dynamic contrastenhanced MRI has shown high diagnostic value in detecting multifocal,multicentric,or contralateral breast cancers.Radiomics is emerging as a promising tool for quantitative tumor evaluation,allowing the extraction of additional quantitative data from radiological imaging acquired with different modalities.Radiomics analysis may provide novel information through the quantification of lesions heterogeneity,that may be relevant in clinical practice for the characterization of breast lesions,prediction of tumor response to systemic therapies and evaluation of prognosis in patients with breast cancers.Several published studies have explored the value of radiomics with good-to-excellent diagnostic and prognostic performances for the evaluation of breast lesions.Particularly,the integrations of radiomics data with other clinical and histopathological parameters have demonstrated to improve the prediction of tumor aggressiveness with high accuracy and provided precise models that will help to guide clinical decisions and patients management.The purpose of this article in to describe the current application of radiomics in breast dynamic contrast-enhanced MRI.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0301503the National Natural Science Foundation of China under Grant Nos 11674358 and 11434015the Instrument Project of the Chinese Academy of Sciences under Grant No YJKYYQ20170025
文摘We experimentally observe the dynamic evolution of atoms in the evaporative cooling, by in-situ imaging the plugged hole of ultracold atoms. Ultracold rubidium atoms confined in a magnetic trap are plugged using a blue-detuned laser beam with a waist of 20 m at a wavelength of 767 nm. We probe the variation of the atomic temperature and width versus the radio frequency in the evaporative cooling. Both the behaviors are in good agreement with the calculation of the trapping potential dressed by the rf signal above the threshold temperature,while deviating from the calculation near the phase transition. To accurately obtain the atomic width, we use the plugged hole as the reference to optimize the optical imaging system by precisely minimizing the artificial structures due to the defocus effect.
文摘Artificial Intelligence (AI) expands its recognition rapidly through the past few years in the context of generating content dynamically, remarkably challenging the human creativity. This study aims to evaluate the efficacy of AI in enhancing personal branding for musicians, particularly in crafting brand images based on emotions received from the artist’s music will improve the audience perceptions regarding the artist’s brand. Study used a quantitative approach for the research, gathering primary data from the survey of 191 people—music lovers, musicians and music producers. The survey focuses on preferences, perceptions, and behaviours related to music consumption and artist branding. The study results demonstrate the awareness and understanding of AI’s role in personal branding within the music industry. Also, results indicate that such an adaptive approach enhances audience perceptions of the artist and strengthens emotional connections. Furthermore, over 50% of the participants indicated a desire to attend live events where an artist’s brand image adapts dynamically to their emotions. The study focuses on novel approaches in personal branding based on the interaction of AI-driven emotional data. In contrast to traditional branding concepts, this study indicates that AI can suggest dynamic and emotionally resonant brand identities for artists. The real time audience response gives proper guidance for the decision-making. This study enriches the knowledge of AI’s applicability to branding processes in the context of the music industry and opens the possibilities for additional advancements in building emotionally appealing brand identities.
文摘An improved estimation of motion vectors of feature points is proposed for tracking moving objects of dynamic image sequence. Feature points are firstly extracted by the improved minimum intensity change （MIC） algorithm. The matching points of these feature points are then determined by adaptive rood pattern searching. Based on the random sample consensus （RANSAC） method, the background motion is finally compensated by the parameters of an affine transform of the background motion. With reasonable morphological filtering, the moving objects are completely extracted from the background, and then tracked accurately. Experimental results show that the improved method is successful on the motion background compensation and offers great promise in tracking moving objects of the dynamic image sequence.
