The introduction of functionalized magnetizable particles for the purification of enzymes or for the multi-use of pre-immobilized biocatalysts offers a great potential for time and cost savings in biotechnological pro...The introduction of functionalized magnetizable particles for the purification of enzymes or for the multi-use of pre-immobilized biocatalysts offers a great potential for time and cost savings in biotechnological process design. The selective separation of the magnetizable particles is performed for example by a high-gradient magnetic separator. In this study FEM and CFD simulations of the magnetic field and the fluid flow field within a filter chamber of a magnetic separator were carried out, to find an optimal separator design. The motion of virtual magnetizable particles was calculated with a one-way coupled Lagrangian approach in order to test many geometric and parametric variations in reduced time. It was found that a flow homogenisator smoothed the fluid flow, so that the linear velocity became nearly equal over the cross section in the direction of flow. Furthermore the retention of magnetizable particles increases with a high total edge length within the filter matrix.展开更多
The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotech...The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotechnical sector. This technique has some advantages especially for the recycling of immobilized enzymes. A new magnetic filter with sight glasses was constructed and produced to study the performance of high-gradient magnetic separation at varied parameters. By optical analysis the buildup of a clogging was identified as the major parameter which affected the separation performance. For the cleaning procedure, a two-phase flow of water with highly dispersed air bubbles was tested which led to a nearly complete cleaning of the filter chamber.展开更多
We present a review of the principal developments in the evolution and synergism of solute and particle migration in a liquid melt in high-gradient magnetic fields and we also describe their effects on the solidificat...We present a review of the principal developments in the evolution and synergism of solute and particle migration in a liquid melt in high-gradient magnetic fields and we also describe their effects on the solidification microstructure of alloys.Diverse areas relevant to various aspects of theory and applications of high-gradient magnetic field-controlled migration of solutes and particles are surveyed.They include introduction,high-gradient magnetic field effects,migration behavior of solute and particles in high-gradient magnetic fields,microstructure evolution induced by high-gradient magnetic fieldcontrolled migrations of solute and particles,and properties of materials modified by high-gradient magnetic field-tailored microstructure.Selected examples of binary and multiphase alloy systems are presented and examined,with the main focus on the correlation between the high-gradient magnetic field-modified migration and the related solidification microstructure evolution.Particular attention is given to the mechanisms responsible for the microstructure evolution induced by highgradient magnetic fields.展开更多
The changes of clay mineral association after high-gradient magnetic separation (HGMS) treatment, and the effects of chemical and physical technologies on concentrating Fe oxides for main soils in central and southern...The changes of clay mineral association after high-gradient magnetic separation (HGMS) treatment, and the effects of chemical and physical technologies on concentrating Fe oxides for main soils in central and southern China were investigated by means of X-ray diffraction (XRD) and chemical analysis methods. Results indicated that the concentrating times of Fe oxides by HGMS treatment were the largest for 0.2-2 μmsize fractions in the examined soils. For the soils in which 2: 1 phyllosilicates were dominant, concentrating times of iron oxides by HGMS treatment were larger than by 5 mol L-1 NaOH treatment. Phyllosili-cates were decreased after HGMS treatment; however, the decrease was less than that of kaorolinite. The goet bite / (goethite + hematie) values in Fe oxides of the soils kept virtually constant after HGMSt reatment.展开更多
The obvious grain refinement of the primary MnSb phase has been observed in the Mn-89.7 wt%Sb alloy directionally solidified under a high-gradient magnetic field.With the application of a high-gradient magnetic field,...The obvious grain refinement of the primary MnSb phase has been observed in the Mn-89.7 wt%Sb alloy directionally solidified under a high-gradient magnetic field.With the application of a high-gradient magnetic field,the morphology of the primary MnSb phase transformed from developed dendritic-like to equiaxed-like,and the grain size decreased by approximately 93%.Refinement of the primary MnSb phase can be attributed to the constituent supercooling in front of the solidification interface,which promoted nucleation of the primary MnSb phase.The constituent supercooling can be linked to the enrichment of the Mn solute induced by the magnetic force and the Lorentz force that drove Mn solute migration and suppressed convection.展开更多
Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significan...Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significant challenging in regulating local phase evolution.Herein,accordion-shaped Co/Co_(3)O_(4)@N-doped carbon nanosheets(Co/Co_(3)O_(4)@NC)with gradient magnetic heterointerfaces have been fabricated via the cooperative high-temperature carbonization and lowtemperature oxidation process.The results indicate that the surface epitaxial growth of crystal Co_(3)O_(4) domains on local Co nanoparticles realizes the adjustment of magnetic-heteroatomic components,which are beneficial for optimizing impedance matching and interfacial polarization.Moreover,gradient magnetic heterointerfaces simultaneously realize magnetic coupling,and long-range magnetic diffraction.Specifically,the synthesized Co/Co_(3)O_(4)@NC absorbents display the strong electromagnetic wave attenuation capability of−53.5 dB at a thickness of 3.0 mm with an effective absorption bandwidth of 5.36 GHz,both are superior to those of single magnetic domains embedded in carbon matrix.This design concept provides us an inspiration in optimizing interfacial polarization,regulating magnetic coupling and promoting electromagnetic wave absorption.展开更多
Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to...Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to make the diagnosis and manage psychiatric disorders remains a distant goal.There have been several studies that examine brain imaging in psychiatric disorders,but more work is needed to elucidate the complexities of the human brain.In this editorial,we examine two articles by Xu et al and Stoyanov et al,that show developments in the direction of using neuroimaging to examine the brains of people with schizo-phrenia and depression.Xu et al used magnetic resonance imaging to examine the brain structure of patients with schizophrenia,in addition to examining neurotransmitter levels as biomarkers.Stoyanov et al used functional magnetic resonance imaging to look at modulation of different neural circuits by diagnostic-specific scales in patients with schizophrenia and depression.These two studies provide crucial evidence in advancing our understanding of the brain in prevalent psychiatric disorders.展开更多
Moderate to severe perinatal hypoxic-ischemic encephalopathy occurs in~1 to 3/1000 live births in high-income countries and is associated with a significant risk of death or neurodevelopmental disability.Detailed asse...Moderate to severe perinatal hypoxic-ischemic encephalopathy occurs in~1 to 3/1000 live births in high-income countries and is associated with a significant risk of death or neurodevelopmental disability.Detailed assessment is important to help identify highrisk infants,to help families,and to support appropriate interventions.A wide range of monitoring tools is available to assess changes over time,including urine and blood biomarkers,neurological examination,and electroencephalography.At present,magnetic resonance imaging is unique as although it is expensive and not suited to monitoring the early evolution of hypoxic-ischemic encephalopathy by a week of life it can provide direct insight into the anatomical changes in the brain after hypoxic-ischemic encephalopathy and so offers strong prognostic information on the long-term outcome after hypoxic-ischemic encephalopathy.This review investigated the temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries,with a particular emphasis on exploring the correlation between the prognostic implications of magnetic resonance imaging scans in the first week of life and their relationship to long-term outcome prediction,particularly for infants treated with therapeutic hypothermia.A comprehensive literature search,from 2016 to 2024,identified 20 pertinent articles.This review highlights that while the optimal timing of magnetic resonance imaging scans is not clear,overall,it suggests that magnetic resonance imaging within the first week of life provides strong prognostic accuracy.Many challenges limit the timing consistency,particularly the need for intensive care and clinical monitoring.Conversely,although most reports examined the prognostic value of scans taken between 4 and 10 days after birth,there is evidence from small numbers of cases that,at times,brain injury may continue to evolve for weeks after birth.This suggests that in the future it will be important to explore a wider range of times after hypoxic-ischemic encephalopathy to fully understand the optimal timing for predicting long-term outcomes.展开更多
Sotos syndrome is characterized by overgrowth features and is caused by alterations in the nuclear receptor binding SET domain protein 1 gene.Attentiondeficit/hyperactivity disorder(ADHD)is considered a neurodevelopme...Sotos syndrome is characterized by overgrowth features and is caused by alterations in the nuclear receptor binding SET domain protein 1 gene.Attentiondeficit/hyperactivity disorder(ADHD)is considered a neurodevelopment and psychiatric disorder in childhood.Genetic characteristics and clinical presentation could play an important role in the diagnosis of Sotos syndrome and ADHD.Magnetic resonance imaging(MRI)has been used to assess medical images in Sotos syndrome and ADHD.The images process is considered to display in MRI while wavelet fusion has been used to integrate distinct images for achieving more complete information in single image in this editorial.In the future,genetic mechanisms and artificial intelligence related to medical images could be used in the clinical diagnosis of Sotos syndrome and ADHD.展开更多
Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and homeostasis.The Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neur...Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and homeostasis.The Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neurodegeneration and ultimately disrupting the operational abilities in daily life,leaving patients incapacitated.Repetitive transcranial magnetic stimulation is a cost-effective,neuro-modulatory technique used for multiple neurological conditions.Over the past two decades,it has been widely used to predict cognitive decline;identify pathophysiological markers;promote neuroplasticity;and assess brain excitability,plasticity,and connectivity.It has also been applied to patients with dementia,because it can yield facilitatory effects on cognition and promote brain recovery after a neurological insult.However,its therapeutic effectiveness at the molecular and synaptic levels has not been elucidated because of a limited number of studies.This study aimed to characterize the neurobiological changes following repetitive transcranial magnetic stimulation treatment,evaluate its effects on synaptic plasticity,and identify the associated mechanisms.This review essentially focuses on changes in the pathology,amyloidogenesis,and clearance pathways,given that amyloid deposition is a major hypothesis in the pathogenesis of Alzheimer’s disease.Apoptotic mechanisms associated with repetitive transcranial magnetic stimulation procedures and different pathways mediating gene transcription,which are closely related to the neural regeneration process,are also highlighted.Finally,we discuss the outcomes of animal studies in which neuroplasticity is modulated and assessed at the structural and functional levels by using repetitive transcranial magnetic stimulation,with the aim to highlight future directions for better clinical translations.展开更多
Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the s...Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the spine.The semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar diseases.It is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation accuracy.This work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra S1.Pseudo-colour mask images were generated and used as ground truth for training the model.The work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley Data.The proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.展开更多
Wireless communications in extreme environments,such as underwater and underground,is an essential technology for interconnecting various devices and enables data transmission and networking.Existing wireless technolo...Wireless communications in extreme environments,such as underwater and underground,is an essential technology for interconnecting various devices and enables data transmission and networking.Existing wireless technologies using electromagnetic(EM)waves face many known problems,such as high path loss,unpredictable multi-path fading,and large antenna size in the lossy medium.In this article,the magnetic induction(MI)based physical layer communication is introduced as a promising solution for wireless transmissions in extreme environments.Specifically,the fundamentals of the MI-based communications are reviewed.Then,with the goal of establishing reliable and low-power links between small-size devices,we review several key physical layer technologies for MI-based communications,including the MIbased signal modulations,magnetic beamforming,and relay transmissions,and summarize their state-of-theart research advances.Finally,the related open issues and challenges in each area are analyzed and presented for future investigations.展开更多
BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)i...BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.展开更多
BACKGROUND An increasing number of studies to date have found preoperative magnetic resonance imaging(MRI)features valuable in predicting the prognosis of rectal cancer(RC).However,research is still lacking on the cor...BACKGROUND An increasing number of studies to date have found preoperative magnetic resonance imaging(MRI)features valuable in predicting the prognosis of rectal cancer(RC).However,research is still lacking on the correlation between preoperative MRI features and the risk of recurrence after radical resection of RC,urgently necessitating further in-depth exploration.AIM To investigate the correlation between preoperative MRI parameters and the risk of recurrence after radical resection of RC to provide an effective tool for predicting postoperative recurrence.METHODS The data of 90 patients who were diagnosed with RC by surgical pathology and underwent radical surgical resection at the Second Affiliated Hospital of Bengbu Medical University between May 2020 and December 2023 were collected through retrospective analysis.General demographic data,MRI data,and tumor markers levels were collected.According to the reviewed data of patients six months after surgery,the clinicians comprehensively assessed the recurrence risk and divided the patients into high recurrence risk(37 cases)and low recurrence risk(53 cases)groups.Independent sample t-test andχ2 test were used to analyze differences between the two groups.A logistic regression model was used to explore the risk factors of the high recurrence risk group,and a clinical prediction model was constructed.The clinical prediction model is presented in the form of a nomogram.The receiver operating characteristic curve,Hosmer-Lemeshow goodness of fit test,calibration curve,and decision curve analysis were used to evaluate the efficacy of the clinical prediction model.RESULTS The detection of positive extramural vascular invasion through preoperative MRI[odds ratio(OR)=4.29,P=0.045],along with elevated carcinoembryonic antigen(OR=1.08,P=0.041),carbohydrate antigen 125(OR=1.19,P=0.034),and carbohydrate antigen 199(OR=1.27,P<0.001)levels,are independent risk factors for increased postoperative recurrence risk in patients with RC.Furthermore,there was a correlation between magnetic resonance based T staging,magnetic resonance based N staging,and circumferential resection margin results determined by MRI and the postoperative recurrence risk.Additionally,when extramural vascular invasion was integrated with tumor markers,the resulting clinical prediction model more effectively identified patients at high risk for postoperative recurrence,thereby providing robust support for clinical decision-making.CONCLUSION The results of this study indicate that preoperative MRI detection is of great importance for predicting the risk of postoperative recurrence in patients with RC.Monitoring these markers helps clinicians identify patients at high risk,allowing for more aggressive treatment and monitoring strategies to improve patient outcomes.展开更多
BACKGROUND Whole-body magnetic resonance imaging(wbMRI)allows general assessment of systemic cancers including lymphomas without radiation burden.AIM To evaluate the diagnostic performance of wbMRI in the staging of d...BACKGROUND Whole-body magnetic resonance imaging(wbMRI)allows general assessment of systemic cancers including lymphomas without radiation burden.AIM To evaluate the diagnostic performance of wbMRI in the staging of diffuse large B-cell lymphoma(DLBCL),determine the value of individual MRI sequences,and assess patients’concerns with wbMRI.METHODS In this single-center prospective study,adult patients newly diagnosed with systemic DLBCL underwent wbMRI on a 3T scanner[diffusion weighted images with background suppression(DWIBS),T2,short tau inversion recovery(STIR),contrast-enhanced T1]and fluorodeoxyglucose(18F-FDG)positron emission tomo-graphy/computed tomography(PET/CT)(reference standard).The involvement of 12 nodal regions and extranodal sites was evaluated on wbMRI and PET/CT.The utility of wbMRI sequences was rated on a five-point scale(0=not useful,4=very useful).Patients received a questionnaire regarding wbMRI.RESULTS Of 60 eligible patients,14(23%)were enrolled and completed the study.The sensitivity of wbMRI in the nodal involvement(182 nodal sites)was 0.84,with 0.99 specificity,positive predictive value of 0.96,negative predictive value of 0.97,and 0.97 accuracy.PET/CT and wbMRI were concordant both in extranodal involvement(13 instances)and staging(κ=1.0).The mean scores of the utility of MRI sequences were 3.71±0.73 for DWIBS,2.64±0.84 for T1,2.14±0.77 for STIR,and 1.29±0.73 for T2(P<0.0001).Patients were mostly concerned about the enclosed environment and duration of the MRI examination(27%of patients).CONCLUSION The wbMRI exhibited excellent sensitivity and specificity in staging DLBCL.DWIBS and contrast-enhanced T1 were rated as the most useful sequences.Patients were less willing to undergo wbMRI as a second examination parallel to PET/CT,especially owing to the long duration and the enclosed environment.展开更多
BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological s...BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological substrates underlying depression,the intricate patterns of disrupted brain network connectivity in adolescents warrant further exploration.AIM To elucidate the neural correlates of adolescent depression by examining brain network connectivity using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS The study cohort comprised 74 depressed adolescents and 59 healthy controls aged 12 to 17 years.Participants underwent rs-fMRI to evaluate functional connectivity within and across critical brain networks,including the visual,default mode network(DMN),dorsal attention,salience,somatomotor,and frontoparietal control networks.RESULTS Analyses revealed pronounced functional disparities within key neural circuits among adolescents with depression.The results demonstrated existence of hemispheric asymmetries characterized by enhanced activity in the left visual network,which contrasted the diminished activity in the right hemisphere.The DMN facilitated increased activity within the left prefrontal cortex and reduced engagement in the right hemisphere,implicating disrupted self-referential and emotional processing mechanisms.Additionally,an overactive right dorsal attention network and a hypoactive salience network were identified,underscoring significant abnormalities in attentional and emotional regulation in adolescent depression.CONCLUSION The findings from this study underscore distinct neural connectivity disruptions in adolescent depression,underscoring the critical role of specific neurobiological markers for precise early diagnosis of adolescent depression.The observed functional asymmetries and network-specific deviations elucidate the complex neurobiological architecture of adolescent depression,supporting the development of targeted therapeutic strategies.展开更多
In this article,we comment on the article by Long et al published in the recent issue of the World Journal of Gastrointestinal Oncology.Rectal cancer patients are at risk for developing metachronous liver metastasis(M...In this article,we comment on the article by Long et al published in the recent issue of the World Journal of Gastrointestinal Oncology.Rectal cancer patients are at risk for developing metachronous liver metastasis(MLM),yet early prediction remains challenging due to variations in tumor heterogeneity and the limitations of traditional diagnostic methods.Therefore,there is an urgent need for noninvasive techniques to improve patient outcomes.Long et al’s study introduces an innovative magnetic resonance imaging(MRI)-based radiomics model that integrates high-throughput imaging data with clinical variables to predict MLM.The study employed a 7:3 split to generate training and validation datasets.The MLM prediction model was constructed using the training set and subsequently validated on the validation set using area under the curve(AUC)and dollar-cost averaging metrics to assess performance,robustness,and generalizability.By employing advanced algorithms,the model provides a non-invasive solution to assess tumor heterogeneity for better metastasis prediction,enabling early intervention and personalized treatment planning.However,variations in MRI parameters,such as differences in scanning resolutions and protocols across facilities,patient heterogeneity(e.g.,age,comorbidities),and external factors like carcinoembryonic antigen levels introduce biases.Additionally,confounding factors such as diagnostic staging methods and patient comorbidities require further validation and adjustment to ensure accuracy and generalizability.With evolving Food and Drug Administration regulations on machine learning models in healthcare,compliance and careful consideration of these regulatory requirements are essential to ensuring safe and effective implementation of this approach in clinical practice.In the future,clinicians may be able to utilize datadriven,patient-centric artificial intelligence(AI)-enhanced imaging tools integrated with clinical data,which would help improve early detection of MLM and optimize personalized treatment strategies.Combining radiomics,genomics,histological data,and demographic information can significantly enhance the accuracy and precision of predictive models.展开更多
Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond timescale.We demonstrate that THz radiation changes its polarity with reversal of the ma...Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond timescale.We demonstrate that THz radiation changes its polarity with reversal of the magnetization applied by the external magnetic field.In addition,it is found that the sign of THz polarity excited from different sides is defined by the thickness of the Fe layer and Fe/dielectric interface.Based on the thickness and symmetry dependences of THz emission,we experimentally distinguish between the two major contributions:ultrafast demagnetization and the anomalous Hall effect.Our experimental results not only enrich understanding of THz electromagnetic generation induced by femtosecond laser pulses but also provide a practical way to access laser-induced ultrafast spin dynamics in magnetic structures.展开更多
BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diff...BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diffusion models for liver fibrosis in one cohort.AIM To evaluate the clinical potential of six diffusion-weighted models in liver fibrosis staging and compare their diagnostic performances.METHODS This prospective study enrolled 59 patients suspected of liver disease and scheduled for liver biopsy and 17 healthy participants.All participants underwent multi-b value DWI.The main DWI-derived parameters included Mono-apparent diffusion coefficient(ADC)from mono-exponential DWI,intravoxel incoherent motion model-derived true diffusion coefficient(IVIM-D),diffusion kurtosis imaging-derived apparent diffusivity(DKI-MD),stretched exponential model-derived distributed diffusion coefficient(SEM-DDC),fractional order calculus(FROC)model-derived diffusion coefficient(FROC-D)and FROC model-derived microstructural quantity(FROC-μ),and continuous-time random-walk(CTRW)model-derived anomalous diffusion coefficient(CTRW-D)and CTRW model-derived temporal diffusion heterogeneity index(CTRW-α).The correlations between DWI-derived parameters and fibrosis stages and the parameters’diagnostic efficacy in detecting significant fibrosis(SF)were assessed and compared.RESULTS CTRW-D(r=-0.356),CTRW-α(r=-0.297),DKI-MD(r=-0.297),FROC-D(r=-0.350),FROC-μ(r=-0.321),IVIM-D(r=-0.251),Mono-ADC(r=-0.362),and SEM-DDC(r=-0.263)were significantly correlated with fibrosis stages.The areas under the ROC curves(AUCs)of the combined index of the six models for distinguishing SF(0.697-0.747)were higher than each of the parameters alone(0.524-0.719).The DWI models’ability to detect SF was similar.The combined index of CTRW model parameters had the highest AUC(0.747).CONCLUSION The DWI models were similarly valuable in distinguishing SF in patients with liver disease.The combined index of CTRW parameters had the highest AUC.展开更多
文摘The introduction of functionalized magnetizable particles for the purification of enzymes or for the multi-use of pre-immobilized biocatalysts offers a great potential for time and cost savings in biotechnological process design. The selective separation of the magnetizable particles is performed for example by a high-gradient magnetic separator. In this study FEM and CFD simulations of the magnetic field and the fluid flow field within a filter chamber of a magnetic separator were carried out, to find an optimal separator design. The motion of virtual magnetizable particles was calculated with a one-way coupled Lagrangian approach in order to test many geometric and parametric variations in reduced time. It was found that a flow homogenisator smoothed the fluid flow, so that the linear velocity became nearly equal over the cross section in the direction of flow. Furthermore the retention of magnetizable particles increases with a high total edge length within the filter matrix.
文摘The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotechnical sector. This technique has some advantages especially for the recycling of immobilized enzymes. A new magnetic filter with sight glasses was constructed and produced to study the performance of high-gradient magnetic separation at varied parameters. By optical analysis the buildup of a clogging was identified as the major parameter which affected the separation performance. For the cleaning procedure, a two-phase flow of water with highly dispersed air bubbles was tested which led to a nearly complete cleaning of the filter chamber.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51425401,51690161,51574073,and 51774086)Fundamental Research Funds for the Central Universities,China(Grant Nos.N170902002 and N170908001)Liaoning Innovative Research Team in University,China(Grant No.LT2017011)
文摘We present a review of the principal developments in the evolution and synergism of solute and particle migration in a liquid melt in high-gradient magnetic fields and we also describe their effects on the solidification microstructure of alloys.Diverse areas relevant to various aspects of theory and applications of high-gradient magnetic field-controlled migration of solutes and particles are surveyed.They include introduction,high-gradient magnetic field effects,migration behavior of solute and particles in high-gradient magnetic fields,microstructure evolution induced by high-gradient magnetic fieldcontrolled migrations of solute and particles,and properties of materials modified by high-gradient magnetic field-tailored microstructure.Selected examples of binary and multiphase alloy systems are presented and examined,with the main focus on the correlation between the high-gradient magnetic field-modified migration and the related solidification microstructure evolution.Particular attention is given to the mechanisms responsible for the microstructure evolution induced by highgradient magnetic fields.
文摘The changes of clay mineral association after high-gradient magnetic separation (HGMS) treatment, and the effects of chemical and physical technologies on concentrating Fe oxides for main soils in central and southern China were investigated by means of X-ray diffraction (XRD) and chemical analysis methods. Results indicated that the concentrating times of Fe oxides by HGMS treatment were the largest for 0.2-2 μmsize fractions in the examined soils. For the soils in which 2: 1 phyllosilicates were dominant, concentrating times of iron oxides by HGMS treatment were larger than by 5 mol L-1 NaOH treatment. Phyllosili-cates were decreased after HGMS treatment; however, the decrease was less than that of kaorolinite. The goet bite / (goethite + hematie) values in Fe oxides of the soils kept virtually constant after HGMSt reatment.
基金supported by the National Key R&D Program of China(Grant No.2021YFB3501404)the fund of the State Key Laboratory of Solidification Processing in NWPU(Grant No.SKLSP202101).
文摘The obvious grain refinement of the primary MnSb phase has been observed in the Mn-89.7 wt%Sb alloy directionally solidified under a high-gradient magnetic field.With the application of a high-gradient magnetic field,the morphology of the primary MnSb phase transformed from developed dendritic-like to equiaxed-like,and the grain size decreased by approximately 93%.Refinement of the primary MnSb phase can be attributed to the constituent supercooling in front of the solidification interface,which promoted nucleation of the primary MnSb phase.The constituent supercooling can be linked to the enrichment of the Mn solute induced by the magnetic force and the Lorentz force that drove Mn solute migration and suppressed convection.
基金financially supported by the National Natural Science Foundation of China(52373271)Science,Technology and Innovation Commission of Shenzhen Municipality under Grant(KCXFZ20201221173004012)+1 种基金National Key Research and Development Program of Shaanxi Province(No.2023-YBNY-271)Open Testing Foundation of the Analytical&Testing Center of Northwestern Polytechnical University(2023T019).
文摘Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significant challenging in regulating local phase evolution.Herein,accordion-shaped Co/Co_(3)O_(4)@N-doped carbon nanosheets(Co/Co_(3)O_(4)@NC)with gradient magnetic heterointerfaces have been fabricated via the cooperative high-temperature carbonization and lowtemperature oxidation process.The results indicate that the surface epitaxial growth of crystal Co_(3)O_(4) domains on local Co nanoparticles realizes the adjustment of magnetic-heteroatomic components,which are beneficial for optimizing impedance matching and interfacial polarization.Moreover,gradient magnetic heterointerfaces simultaneously realize magnetic coupling,and long-range magnetic diffraction.Specifically,the synthesized Co/Co_(3)O_(4)@NC absorbents display the strong electromagnetic wave attenuation capability of−53.5 dB at a thickness of 3.0 mm with an effective absorption bandwidth of 5.36 GHz,both are superior to those of single magnetic domains embedded in carbon matrix.This design concept provides us an inspiration in optimizing interfacial polarization,regulating magnetic coupling and promoting electromagnetic wave absorption.
文摘Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to make the diagnosis and manage psychiatric disorders remains a distant goal.There have been several studies that examine brain imaging in psychiatric disorders,but more work is needed to elucidate the complexities of the human brain.In this editorial,we examine two articles by Xu et al and Stoyanov et al,that show developments in the direction of using neuroimaging to examine the brains of people with schizo-phrenia and depression.Xu et al used magnetic resonance imaging to examine the brain structure of patients with schizophrenia,in addition to examining neurotransmitter levels as biomarkers.Stoyanov et al used functional magnetic resonance imaging to look at modulation of different neural circuits by diagnostic-specific scales in patients with schizophrenia and depression.These two studies provide crucial evidence in advancing our understanding of the brain in prevalent psychiatric disorders.
基金supported by a grant from the Health Research New Zealand(HRC)22/559(to AJG and LB)。
文摘Moderate to severe perinatal hypoxic-ischemic encephalopathy occurs in~1 to 3/1000 live births in high-income countries and is associated with a significant risk of death or neurodevelopmental disability.Detailed assessment is important to help identify highrisk infants,to help families,and to support appropriate interventions.A wide range of monitoring tools is available to assess changes over time,including urine and blood biomarkers,neurological examination,and electroencephalography.At present,magnetic resonance imaging is unique as although it is expensive and not suited to monitoring the early evolution of hypoxic-ischemic encephalopathy by a week of life it can provide direct insight into the anatomical changes in the brain after hypoxic-ischemic encephalopathy and so offers strong prognostic information on the long-term outcome after hypoxic-ischemic encephalopathy.This review investigated the temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries,with a particular emphasis on exploring the correlation between the prognostic implications of magnetic resonance imaging scans in the first week of life and their relationship to long-term outcome prediction,particularly for infants treated with therapeutic hypothermia.A comprehensive literature search,from 2016 to 2024,identified 20 pertinent articles.This review highlights that while the optimal timing of magnetic resonance imaging scans is not clear,overall,it suggests that magnetic resonance imaging within the first week of life provides strong prognostic accuracy.Many challenges limit the timing consistency,particularly the need for intensive care and clinical monitoring.Conversely,although most reports examined the prognostic value of scans taken between 4 and 10 days after birth,there is evidence from small numbers of cases that,at times,brain injury may continue to evolve for weeks after birth.This suggests that in the future it will be important to explore a wider range of times after hypoxic-ischemic encephalopathy to fully understand the optimal timing for predicting long-term outcomes.
基金Supported by Natural Science Foundation of Shanghai,No.17ZR1431400National Key R and D Program of China,No.2017YFA0103902.
文摘Sotos syndrome is characterized by overgrowth features and is caused by alterations in the nuclear receptor binding SET domain protein 1 gene.Attentiondeficit/hyperactivity disorder(ADHD)is considered a neurodevelopment and psychiatric disorder in childhood.Genetic characteristics and clinical presentation could play an important role in the diagnosis of Sotos syndrome and ADHD.Magnetic resonance imaging(MRI)has been used to assess medical images in Sotos syndrome and ADHD.The images process is considered to display in MRI while wavelet fusion has been used to integrate distinct images for achieving more complete information in single image in this editorial.In the future,genetic mechanisms and artificial intelligence related to medical images could be used in the clinical diagnosis of Sotos syndrome and ADHD.
基金supported by the Hefei Comprehensive National Science Center Hefei Brain Project(to KW)the National Natural Science Foundation of China,Nos.31970979(to KW),82101498(to XW)the STI2030-Major Projects,No.2021ZD0201800(to PH).
文摘Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and homeostasis.The Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neurodegeneration and ultimately disrupting the operational abilities in daily life,leaving patients incapacitated.Repetitive transcranial magnetic stimulation is a cost-effective,neuro-modulatory technique used for multiple neurological conditions.Over the past two decades,it has been widely used to predict cognitive decline;identify pathophysiological markers;promote neuroplasticity;and assess brain excitability,plasticity,and connectivity.It has also been applied to patients with dementia,because it can yield facilitatory effects on cognition and promote brain recovery after a neurological insult.However,its therapeutic effectiveness at the molecular and synaptic levels has not been elucidated because of a limited number of studies.This study aimed to characterize the neurobiological changes following repetitive transcranial magnetic stimulation treatment,evaluate its effects on synaptic plasticity,and identify the associated mechanisms.This review essentially focuses on changes in the pathology,amyloidogenesis,and clearance pathways,given that amyloid deposition is a major hypothesis in the pathogenesis of Alzheimer’s disease.Apoptotic mechanisms associated with repetitive transcranial magnetic stimulation procedures and different pathways mediating gene transcription,which are closely related to the neural regeneration process,are also highlighted.Finally,we discuss the outcomes of animal studies in which neuroplasticity is modulated and assessed at the structural and functional levels by using repetitive transcranial magnetic stimulation,with the aim to highlight future directions for better clinical translations.
文摘Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the spine.The semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar diseases.It is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation accuracy.This work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra S1.Pseudo-colour mask images were generated and used as ground truth for training the model.The work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley Data.The proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.
文摘Wireless communications in extreme environments,such as underwater and underground,is an essential technology for interconnecting various devices and enables data transmission and networking.Existing wireless technologies using electromagnetic(EM)waves face many known problems,such as high path loss,unpredictable multi-path fading,and large antenna size in the lossy medium.In this article,the magnetic induction(MI)based physical layer communication is introduced as a promising solution for wireless transmissions in extreme environments.Specifically,the fundamentals of the MI-based communications are reviewed.Then,with the goal of establishing reliable and low-power links between small-size devices,we review several key physical layer technologies for MI-based communications,including the MIbased signal modulations,magnetic beamforming,and relay transmissions,and summarize their state-of-theart research advances.Finally,the related open issues and challenges in each area are analyzed and presented for future investigations.
基金Supported by Bozhou Key Research and Development Project,No.bzzc2020031.
文摘BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.
文摘BACKGROUND An increasing number of studies to date have found preoperative magnetic resonance imaging(MRI)features valuable in predicting the prognosis of rectal cancer(RC).However,research is still lacking on the correlation between preoperative MRI features and the risk of recurrence after radical resection of RC,urgently necessitating further in-depth exploration.AIM To investigate the correlation between preoperative MRI parameters and the risk of recurrence after radical resection of RC to provide an effective tool for predicting postoperative recurrence.METHODS The data of 90 patients who were diagnosed with RC by surgical pathology and underwent radical surgical resection at the Second Affiliated Hospital of Bengbu Medical University between May 2020 and December 2023 were collected through retrospective analysis.General demographic data,MRI data,and tumor markers levels were collected.According to the reviewed data of patients six months after surgery,the clinicians comprehensively assessed the recurrence risk and divided the patients into high recurrence risk(37 cases)and low recurrence risk(53 cases)groups.Independent sample t-test andχ2 test were used to analyze differences between the two groups.A logistic regression model was used to explore the risk factors of the high recurrence risk group,and a clinical prediction model was constructed.The clinical prediction model is presented in the form of a nomogram.The receiver operating characteristic curve,Hosmer-Lemeshow goodness of fit test,calibration curve,and decision curve analysis were used to evaluate the efficacy of the clinical prediction model.RESULTS The detection of positive extramural vascular invasion through preoperative MRI[odds ratio(OR)=4.29,P=0.045],along with elevated carcinoembryonic antigen(OR=1.08,P=0.041),carbohydrate antigen 125(OR=1.19,P=0.034),and carbohydrate antigen 199(OR=1.27,P<0.001)levels,are independent risk factors for increased postoperative recurrence risk in patients with RC.Furthermore,there was a correlation between magnetic resonance based T staging,magnetic resonance based N staging,and circumferential resection margin results determined by MRI and the postoperative recurrence risk.Additionally,when extramural vascular invasion was integrated with tumor markers,the resulting clinical prediction model more effectively identified patients at high risk for postoperative recurrence,thereby providing robust support for clinical decision-making.CONCLUSION The results of this study indicate that preoperative MRI detection is of great importance for predicting the risk of postoperative recurrence in patients with RC.Monitoring these markers helps clinicians identify patients at high risk,allowing for more aggressive treatment and monitoring strategies to improve patient outcomes.
基金Supported by the Czech Ministry of Health,General University Hospital in Prague,No.VFN00064165。
文摘BACKGROUND Whole-body magnetic resonance imaging(wbMRI)allows general assessment of systemic cancers including lymphomas without radiation burden.AIM To evaluate the diagnostic performance of wbMRI in the staging of diffuse large B-cell lymphoma(DLBCL),determine the value of individual MRI sequences,and assess patients’concerns with wbMRI.METHODS In this single-center prospective study,adult patients newly diagnosed with systemic DLBCL underwent wbMRI on a 3T scanner[diffusion weighted images with background suppression(DWIBS),T2,short tau inversion recovery(STIR),contrast-enhanced T1]and fluorodeoxyglucose(18F-FDG)positron emission tomo-graphy/computed tomography(PET/CT)(reference standard).The involvement of 12 nodal regions and extranodal sites was evaluated on wbMRI and PET/CT.The utility of wbMRI sequences was rated on a five-point scale(0=not useful,4=very useful).Patients received a questionnaire regarding wbMRI.RESULTS Of 60 eligible patients,14(23%)were enrolled and completed the study.The sensitivity of wbMRI in the nodal involvement(182 nodal sites)was 0.84,with 0.99 specificity,positive predictive value of 0.96,negative predictive value of 0.97,and 0.97 accuracy.PET/CT and wbMRI were concordant both in extranodal involvement(13 instances)and staging(κ=1.0).The mean scores of the utility of MRI sequences were 3.71±0.73 for DWIBS,2.64±0.84 for T1,2.14±0.77 for STIR,and 1.29±0.73 for T2(P<0.0001).Patients were mostly concerned about the enclosed environment and duration of the MRI examination(27%of patients).CONCLUSION The wbMRI exhibited excellent sensitivity and specificity in staging DLBCL.DWIBS and contrast-enhanced T1 were rated as the most useful sequences.Patients were less willing to undergo wbMRI as a second examination parallel to PET/CT,especially owing to the long duration and the enclosed environment.
基金Supported by the Medical Research Project of the Chongqing Municipal Health Commission,No.2024WSJK110.
文摘BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological substrates underlying depression,the intricate patterns of disrupted brain network connectivity in adolescents warrant further exploration.AIM To elucidate the neural correlates of adolescent depression by examining brain network connectivity using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS The study cohort comprised 74 depressed adolescents and 59 healthy controls aged 12 to 17 years.Participants underwent rs-fMRI to evaluate functional connectivity within and across critical brain networks,including the visual,default mode network(DMN),dorsal attention,salience,somatomotor,and frontoparietal control networks.RESULTS Analyses revealed pronounced functional disparities within key neural circuits among adolescents with depression.The results demonstrated existence of hemispheric asymmetries characterized by enhanced activity in the left visual network,which contrasted the diminished activity in the right hemisphere.The DMN facilitated increased activity within the left prefrontal cortex and reduced engagement in the right hemisphere,implicating disrupted self-referential and emotional processing mechanisms.Additionally,an overactive right dorsal attention network and a hypoactive salience network were identified,underscoring significant abnormalities in attentional and emotional regulation in adolescent depression.CONCLUSION The findings from this study underscore distinct neural connectivity disruptions in adolescent depression,underscoring the critical role of specific neurobiological markers for precise early diagnosis of adolescent depression.The observed functional asymmetries and network-specific deviations elucidate the complex neurobiological architecture of adolescent depression,supporting the development of targeted therapeutic strategies.
文摘In this article,we comment on the article by Long et al published in the recent issue of the World Journal of Gastrointestinal Oncology.Rectal cancer patients are at risk for developing metachronous liver metastasis(MLM),yet early prediction remains challenging due to variations in tumor heterogeneity and the limitations of traditional diagnostic methods.Therefore,there is an urgent need for noninvasive techniques to improve patient outcomes.Long et al’s study introduces an innovative magnetic resonance imaging(MRI)-based radiomics model that integrates high-throughput imaging data with clinical variables to predict MLM.The study employed a 7:3 split to generate training and validation datasets.The MLM prediction model was constructed using the training set and subsequently validated on the validation set using area under the curve(AUC)and dollar-cost averaging metrics to assess performance,robustness,and generalizability.By employing advanced algorithms,the model provides a non-invasive solution to assess tumor heterogeneity for better metastasis prediction,enabling early intervention and personalized treatment planning.However,variations in MRI parameters,such as differences in scanning resolutions and protocols across facilities,patient heterogeneity(e.g.,age,comorbidities),and external factors like carcinoembryonic antigen levels introduce biases.Additionally,confounding factors such as diagnostic staging methods and patient comorbidities require further validation and adjustment to ensure accuracy and generalizability.With evolving Food and Drug Administration regulations on machine learning models in healthcare,compliance and careful consideration of these regulatory requirements are essential to ensuring safe and effective implementation of this approach in clinical practice.In the future,clinicians may be able to utilize datadriven,patient-centric artificial intelligence(AI)-enhanced imaging tools integrated with clinical data,which would help improve early detection of MLM and optimize personalized treatment strategies.Combining radiomics,genomics,histological data,and demographic information can significantly enhance the accuracy and precision of predictive models.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFF0719200 and 2022YFA1404004)the National Natural Science Foundation of China(Grant Nos.61988102,62322115,61975110,and 62335012)+3 种基金the 111 Project(Grant No.D18014)the Key Project supported by Science and Technology Commission Shanghai Municipality(Grant No.YDZX20193100004960)Science and Technology Commission of Shanghai Municipality(Grant No.22JC1400200)General Administration of Customs People’s Republic of China(Grant No.2019HK006)。
文摘Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond timescale.We demonstrate that THz radiation changes its polarity with reversal of the magnetization applied by the external magnetic field.In addition,it is found that the sign of THz polarity excited from different sides is defined by the thickness of the Fe layer and Fe/dielectric interface.Based on the thickness and symmetry dependences of THz emission,we experimentally distinguish between the two major contributions:ultrafast demagnetization and the anomalous Hall effect.Our experimental results not only enrich understanding of THz electromagnetic generation induced by femtosecond laser pulses but also provide a practical way to access laser-induced ultrafast spin dynamics in magnetic structures.
基金the Cuiying Scientific and Technological Innovation Program of Lanzhou University Second Hospital,NO.CY2021-QNB09the Science and Technology Project of Gansu Province,NO.21JR11RA122+1 种基金Department of Education of Gansu Province:Innovation Fund Project,NO.2022B-056Gansu Province Clinical Research Center for Functional and Molecular Imaging,NO.21JR7RA438.
文摘BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diffusion models for liver fibrosis in one cohort.AIM To evaluate the clinical potential of six diffusion-weighted models in liver fibrosis staging and compare their diagnostic performances.METHODS This prospective study enrolled 59 patients suspected of liver disease and scheduled for liver biopsy and 17 healthy participants.All participants underwent multi-b value DWI.The main DWI-derived parameters included Mono-apparent diffusion coefficient(ADC)from mono-exponential DWI,intravoxel incoherent motion model-derived true diffusion coefficient(IVIM-D),diffusion kurtosis imaging-derived apparent diffusivity(DKI-MD),stretched exponential model-derived distributed diffusion coefficient(SEM-DDC),fractional order calculus(FROC)model-derived diffusion coefficient(FROC-D)and FROC model-derived microstructural quantity(FROC-μ),and continuous-time random-walk(CTRW)model-derived anomalous diffusion coefficient(CTRW-D)and CTRW model-derived temporal diffusion heterogeneity index(CTRW-α).The correlations between DWI-derived parameters and fibrosis stages and the parameters’diagnostic efficacy in detecting significant fibrosis(SF)were assessed and compared.RESULTS CTRW-D(r=-0.356),CTRW-α(r=-0.297),DKI-MD(r=-0.297),FROC-D(r=-0.350),FROC-μ(r=-0.321),IVIM-D(r=-0.251),Mono-ADC(r=-0.362),and SEM-DDC(r=-0.263)were significantly correlated with fibrosis stages.The areas under the ROC curves(AUCs)of the combined index of the six models for distinguishing SF(0.697-0.747)were higher than each of the parameters alone(0.524-0.719).The DWI models’ability to detect SF was similar.The combined index of CTRW model parameters had the highest AUC(0.747).CONCLUSION The DWI models were similarly valuable in distinguishing SF in patients with liver disease.The combined index of CTRW parameters had the highest AUC.